...Judged foremostly on the basis of innovation, though playability is considered.
EDIT: Also, it would be interesting to hear people's feedback on this.
RPG - 13
-- pedit5 (1974) -- first dungeon crawl game
-- Wizardry (1981) -- featured vastly more intuitive layout and interface than earlier CRPGs
-- Ultima III: Exodus (1983) -- popularized non-text based graphics in RPGs
-- NetHack (1987) -- refined formula of Rogue; popularized CRPGs
-- Dragon Warrior (1989)-- first wildly successful JRPG; subsequently influenced FF/DQ series'
-- Ultima Underworld (1992) -- first CRPG to use real 3D graphics; influenced Wolfenstein 3D
-- Diablo (1996) -- popularized point-and-click CRPGs
-- Fallout (1997) -- helped revive non-linear gameplay and moral choices in CRPGs
-- Final Fantasy VII (1997) -- used PSOne architecture to influentially modernize JRPGs
-- Ultima Online (1997) -- first widely successful MMORPG; influenced Everquest & WoW heavily
-- Pokemon Red/Blue (1998) -- started "fighting monsters" craze; popularized Game Boy link cable
-- Deus Ex (2000) -- influentially fused FPS and CRPG gameplay
-- The Elder Scrolls III: Morrowind (2002) -- fused "sandbox" design with CRPG gameplay
2D Platformer - 13
-- Donkey Kong (1981) -- first decided 'platformer' where player could jump over gaps; obstacles
-- Pitfall! (1982) -- popularized platformer levels spanning multiple screens
-- Legend of Kage (1984) -- first platformer to scroll fluidly in all directions
-- Knight Lore (1984) -- first successful isometric platformer; influenced Land Stalker, SMRPG
-- Super Mario Bros. (1985) -- saved games from '83 crash; playability and vastness influential
-- Contra (1987) -- helped popularize two-player simultaneous gameplay; multi-directional firing
-- Metroid (1987) -- helped popularize non-linear 'Metroidvania' subgenre of platformers
-- Prince of Persia (1989) -- rotoscoping allowed intensive detail; popularized PC platformers
-- Super Mario Bros. 3 (1989) -- set entirely new standard for depth of future platformers
-- Commander Keen (1990) -- first DOS platformer to feature smooth, side-scrolling graphics
-- Sonic the Hedgehog (1991) -- popularized speed in platformers; Genesis' killer app
-- Super Metroid (1994) -- helped sophisticate platformers; excellent graphics, sound
-- Castlevania: SOTN (1997) -- featured non-linear levels and well-integrated RPG elements
FPS - 11
-- Maze War (1974) -- proto-FPS; pioneered concept of shooting at opponents in 3D environments
-- Wolfenstein 3D (1992) -- created FPS template; used texture mapping to achieve 3D 'feel'
-- DOOM (1994) -- created 'deathmatches'; popularized the FPS genre; refined Wolfenstein formula
-- System Shock (1994) -- first FPS to allow players 3D range of movement; sophisticated genre
-- Descent (1995) -- first FPS to render in 3D using polygon meshes; feature six degrees freedom
-- Quake (1996) -- popularized robust Internet gaming; mod culture including CTF and TF
-- GoldenEye 007 (1997) -- popularized console shooters; helped sophisticate FPS genre
-- Jedi Knight: Dark Forces II (1997) -- template for melee in FPS; groundbreaking presentation
-- Half-Life (1998) -- popularized storytelling in FPS, use of NPCs; featured groundbreaking AI
-- Metroid Prime (2002) -- arguably the finest example of its genre in the '00s
-- Half-Life 2 (2005) -- popularized using physics in FPS genre; refined FPS artistry, narration
Adventure - 8
-- Colossal Cave Adventure (1976) -- first text-based adventure game
-- Zork I (1980) -- popularized text-based adventure games
-- Mystery House (1980) -- first adventure game to feature graphical interface
-- King's Quest (1984) -- first graphical adventure game not in first-person
-- The Secret of Monkey Island (1990) -- first fully-realized SCUMM-engine adventure
-- Myst (1993) -- popularized CD-Rs; first adventure game to heavily use multimedia content
-- Grim Fandango (1998) -- first critically sucessful 'real' 3D adventure game
-- Shenmue (2000) -- apex of Japanese adventure games; influential use of ATBs, sandbox world
Strategy - 5
-- Artillery (1980) -- first artillery game; influenced Worms, GunBound
-- M.U.L.E. (1983) -- pioneered single-console multiplay; influenced strategy genre
-- Sid Meier's Pirates! (1987) -- Meier's first successful foray into strategy genre
-- Civilization (1991) -- first highly successful implementation of 4X conceit
-- X-COM: UFO Defense (1993) -- apex of turn-based tactics genre
RTS - 5
-- Herzog Zwei (1989) -- inarguably the first real-time strategy game
-- Dune II: The Building of a Dynasty (1992) -- established conventions of RTS genre
-- Command & Conquer (1995) -- caused commercial flourishing of RTS genre
-- StarCraft (1998) -- made online RTS gaming wildly popular; used entirely distinct teams
-- Homeworld (1999) -- one of first fully-3D RTS; featured movement in four directions
Racing - 5
-- Night Racer (1977) -- first racing game to extend racing genre into 3D
-- Pole Position (1982) -- popularized racing genre; featured enemy AI, real racing circuit
-- Virtua Racing (1992) -- first racer to feature 3D graphics coupled with high accessibility
-- Super Mario Kart (1992) -- departed from 'realistic' paradigm; popularized 'mascot' racers
-- Gran Turismo (1997) -- unprecedented realism for a racing sim; started GT franchise
Fighting - 5
-- Karate Champ (1984) -- popularized side-perspective; initiated fighting genre
-- Street Fighter II (1991) -- popularized fighting genre; introduced many of its conventions
-- Virtua Fighter (1993) -- first fighter to feature fully-3D graphics
-- Super Smash Bros. (1999) -- entirely different than previous fighters; begun SSB franchise
-- Soul Calibur (2000) -- influential in its curbing of the complexity of nineties-era fighters
Puzzle - 5
-- Lode Runner (1983) -- one of first character-controlled puzzlers; popularized level editor
-- Tetris (1986) -- first wildly successful puzzle game; influenced nonillion variants
-- Lemmings (1991) -- popularized multiple character control puzzle games
-- Bust-A-Move (1994) -- arguably most popular 'falling blocks' game to succeed Tetris
-- Portal (2007) -- popularized first-person puzzle games; innovatively designed
Arcade - 4
-- Pong (1972) -- popularized coin-operated video game machines
-- Space Invaders (1978) -- helped games reach mainstream; started 'high scores'
-- Pac-Man (1980) -- caused industry to diverge from Pong and Space Invaders knock-offs
-- Battlezone (1980) -- use of vectored 3D graphics made it effectively first VR game
Sports - 4
-- Intellivision World Series Baseball (1982) -- first sports game with voicing; camera angles
-- Madden Football (1990) -- begun EA Sports console tradition; advent of Madden series
-- The Sensible World of Soccer (1994) -- most ambitious sports sim developed; influenced genre
-- Tony Hawk's Pro Skater (1999) -- popularized games based on extreme sports
Flight - 4
-- Spacewar! (1961) -- first multi-player computer game; popularized space shmup genre
-- Star Raiders (1979) -- out-of-the-cockpit camera innovative; influenced Wing Commander
-- Wing Commander II (1991) -- some of industry's first voice acting; sophisticated genre
-- Star Wars: TIE Fighter (1994) -- apex of flight genre; possesed many innovative features
Action/Adventure - 3
-- The Legend of Zelda (1986) -- combined several genres; popularized nonlinear CRPG design
-- The Legend of Zelda: Ocarina of Time (1998) -- benchmark for 3D design; revitalized Zelda IP
-- Grand Theft Auto III (2001) -- initiated 'sandbox era' of design; influenced countless titles
Simulation - 3
-- SimCity (1989) -- popularized 'city-building' conceit; influenced Sim titles, ActRaiser
-- Populous (1989) -- first 'God' game; began career of Peter Molyneux
-- The Sims (2000) -- popularized 'life simulation' games; expanded computer-game demographic
3D Platformer - 3
-- Alpha Waves (1990) -- first true 3D platformer
-- Super Mario 64 (1996) -- increased the credibility of and refined 3D platformer genre
-- Space Station Silicon Valley (1998) -- intelligent precursor to 3D GTA iterations
Stealth - 3
-- Metal Gear (1987) -- first ever stealth video game made
-- Thief: The Dark Project (1998) -- first use of light, shadow, audio puzzles in stealth game
-- Metal Gear Solid (1998) -- popularized stealth genre; influenced storytelling in games
Survival Horror - 3
-- Sweet Home (1989, JP only) -- pioneered conventions of survival horror genre; influenced RE
-- Alone in the Dark (1993) -- survival horror forefather; mixed polygons and 2D prerendering
-- Resident Evil (1996) -- popularized survival horror genre
Music - 2
-- Dance Dance Revolution (1998) -- increased profile of music games; spawned global phenomena
-- Guitar Hero (2005) -- popularized player use of pseudo-instrumentation in music games
FACTS
Games from the '60s: 1
Games from the '70s: 7
Games from the '80s: 31
Games from the '90s: 51
Games from the '00s: 10
Most Featured Developers:
-- Nintendo (12)
-- Konami (5)
-- Sega (4)
-- LucasArts (4)
-- id (4)
-- Looking Glass Studios (3)
-- DMA Design/Rockstar North (3)
-- Origin Systems (3)
-- Taito (3)
-- Valve (3)
-- Namco (3)
-- Capcom (3)
-- Sierra (2)
-- Blizzard (2)
-- Activision (2)
-- Maxis (2)
-- Westwood (2)
-- Atari (2)
-- MicroProse (2)
EDIT: Also, it would be interesting to hear people's feedback on this.
RPG - 13
-- pedit5 (1974) -- first dungeon crawl game
-- Wizardry (1981) -- featured vastly more intuitive layout and interface than earlier CRPGs
-- Ultima III: Exodus (1983) -- popularized non-text based graphics in RPGs
-- NetHack (1987) -- refined formula of Rogue; popularized CRPGs
-- Dragon Warrior (1989)-- first wildly successful JRPG; subsequently influenced FF/DQ series'
-- Ultima Underworld (1992) -- first CRPG to use real 3D graphics; influenced Wolfenstein 3D
-- Diablo (1996) -- popularized point-and-click CRPGs
-- Fallout (1997) -- helped revive non-linear gameplay and moral choices in CRPGs
-- Final Fantasy VII (1997) -- used PSOne architecture to influentially modernize JRPGs
-- Ultima Online (1997) -- first widely successful MMORPG; influenced Everquest & WoW heavily
-- Pokemon Red/Blue (1998) -- started "fighting monsters" craze; popularized Game Boy link cable
-- Deus Ex (2000) -- influentially fused FPS and CRPG gameplay
-- The Elder Scrolls III: Morrowind (2002) -- fused "sandbox" design with CRPG gameplay
2D Platformer - 13
-- Donkey Kong (1981) -- first decided 'platformer' where player could jump over gaps; obstacles
-- Pitfall! (1982) -- popularized platformer levels spanning multiple screens
-- Legend of Kage (1984) -- first platformer to scroll fluidly in all directions
-- Knight Lore (1984) -- first successful isometric platformer; influenced Land Stalker, SMRPG
-- Super Mario Bros. (1985) -- saved games from '83 crash; playability and vastness influential
-- Contra (1987) -- helped popularize two-player simultaneous gameplay; multi-directional firing
-- Metroid (1987) -- helped popularize non-linear 'Metroidvania' subgenre of platformers
-- Prince of Persia (1989) -- rotoscoping allowed intensive detail; popularized PC platformers
-- Super Mario Bros. 3 (1989) -- set entirely new standard for depth of future platformers
-- Commander Keen (1990) -- first DOS platformer to feature smooth, side-scrolling graphics
-- Sonic the Hedgehog (1991) -- popularized speed in platformers; Genesis' killer app
-- Super Metroid (1994) -- helped sophisticate platformers; excellent graphics, sound
-- Castlevania: SOTN (1997) -- featured non-linear levels and well-integrated RPG elements
FPS - 11
-- Maze War (1974) -- proto-FPS; pioneered concept of shooting at opponents in 3D environments
-- Wolfenstein 3D (1992) -- created FPS template; used texture mapping to achieve 3D 'feel'
-- DOOM (1994) -- created 'deathmatches'; popularized the FPS genre; refined Wolfenstein formula
-- System Shock (1994) -- first FPS to allow players 3D range of movement; sophisticated genre
-- Descent (1995) -- first FPS to render in 3D using polygon meshes; feature six degrees freedom
-- Quake (1996) -- popularized robust Internet gaming; mod culture including CTF and TF
-- GoldenEye 007 (1997) -- popularized console shooters; helped sophisticate FPS genre
-- Jedi Knight: Dark Forces II (1997) -- template for melee in FPS; groundbreaking presentation
-- Half-Life (1998) -- popularized storytelling in FPS, use of NPCs; featured groundbreaking AI
-- Metroid Prime (2002) -- arguably the finest example of its genre in the '00s
-- Half-Life 2 (2005) -- popularized using physics in FPS genre; refined FPS artistry, narration
Adventure - 8
-- Colossal Cave Adventure (1976) -- first text-based adventure game
-- Zork I (1980) -- popularized text-based adventure games
-- Mystery House (1980) -- first adventure game to feature graphical interface
-- King's Quest (1984) -- first graphical adventure game not in first-person
-- The Secret of Monkey Island (1990) -- first fully-realized SCUMM-engine adventure
-- Myst (1993) -- popularized CD-Rs; first adventure game to heavily use multimedia content
-- Grim Fandango (1998) -- first critically sucessful 'real' 3D adventure game
-- Shenmue (2000) -- apex of Japanese adventure games; influential use of ATBs, sandbox world
Strategy - 5
-- Artillery (1980) -- first artillery game; influenced Worms, GunBound
-- M.U.L.E. (1983) -- pioneered single-console multiplay; influenced strategy genre
-- Sid Meier's Pirates! (1987) -- Meier's first successful foray into strategy genre
-- Civilization (1991) -- first highly successful implementation of 4X conceit
-- X-COM: UFO Defense (1993) -- apex of turn-based tactics genre
RTS - 5
-- Herzog Zwei (1989) -- inarguably the first real-time strategy game
-- Dune II: The Building of a Dynasty (1992) -- established conventions of RTS genre
-- Command & Conquer (1995) -- caused commercial flourishing of RTS genre
-- StarCraft (1998) -- made online RTS gaming wildly popular; used entirely distinct teams
-- Homeworld (1999) -- one of first fully-3D RTS; featured movement in four directions
Racing - 5
-- Night Racer (1977) -- first racing game to extend racing genre into 3D
-- Pole Position (1982) -- popularized racing genre; featured enemy AI, real racing circuit
-- Virtua Racing (1992) -- first racer to feature 3D graphics coupled with high accessibility
-- Super Mario Kart (1992) -- departed from 'realistic' paradigm; popularized 'mascot' racers
-- Gran Turismo (1997) -- unprecedented realism for a racing sim; started GT franchise
Fighting - 5
-- Karate Champ (1984) -- popularized side-perspective; initiated fighting genre
-- Street Fighter II (1991) -- popularized fighting genre; introduced many of its conventions
-- Virtua Fighter (1993) -- first fighter to feature fully-3D graphics
-- Super Smash Bros. (1999) -- entirely different than previous fighters; begun SSB franchise
-- Soul Calibur (2000) -- influential in its curbing of the complexity of nineties-era fighters
Puzzle - 5
-- Lode Runner (1983) -- one of first character-controlled puzzlers; popularized level editor
-- Tetris (1986) -- first wildly successful puzzle game; influenced nonillion variants
-- Lemmings (1991) -- popularized multiple character control puzzle games
-- Bust-A-Move (1994) -- arguably most popular 'falling blocks' game to succeed Tetris
-- Portal (2007) -- popularized first-person puzzle games; innovatively designed
Arcade - 4
-- Pong (1972) -- popularized coin-operated video game machines
-- Space Invaders (1978) -- helped games reach mainstream; started 'high scores'
-- Pac-Man (1980) -- caused industry to diverge from Pong and Space Invaders knock-offs
-- Battlezone (1980) -- use of vectored 3D graphics made it effectively first VR game
Sports - 4
-- Intellivision World Series Baseball (1982) -- first sports game with voicing; camera angles
-- Madden Football (1990) -- begun EA Sports console tradition; advent of Madden series
-- The Sensible World of Soccer (1994) -- most ambitious sports sim developed; influenced genre
-- Tony Hawk's Pro Skater (1999) -- popularized games based on extreme sports
Flight - 4
-- Spacewar! (1961) -- first multi-player computer game; popularized space shmup genre
-- Star Raiders (1979) -- out-of-the-cockpit camera innovative; influenced Wing Commander
-- Wing Commander II (1991) -- some of industry's first voice acting; sophisticated genre
-- Star Wars: TIE Fighter (1994) -- apex of flight genre; possesed many innovative features
Action/Adventure - 3
-- The Legend of Zelda (1986) -- combined several genres; popularized nonlinear CRPG design
-- The Legend of Zelda: Ocarina of Time (1998) -- benchmark for 3D design; revitalized Zelda IP
-- Grand Theft Auto III (2001) -- initiated 'sandbox era' of design; influenced countless titles
Simulation - 3
-- SimCity (1989) -- popularized 'city-building' conceit; influenced Sim titles, ActRaiser
-- Populous (1989) -- first 'God' game; began career of Peter Molyneux
-- The Sims (2000) -- popularized 'life simulation' games; expanded computer-game demographic
3D Platformer - 3
-- Alpha Waves (1990) -- first true 3D platformer
-- Super Mario 64 (1996) -- increased the credibility of and refined 3D platformer genre
-- Space Station Silicon Valley (1998) -- intelligent precursor to 3D GTA iterations
Stealth - 3
-- Metal Gear (1987) -- first ever stealth video game made
-- Thief: The Dark Project (1998) -- first use of light, shadow, audio puzzles in stealth game
-- Metal Gear Solid (1998) -- popularized stealth genre; influenced storytelling in games
Survival Horror - 3
-- Sweet Home (1989, JP only) -- pioneered conventions of survival horror genre; influenced RE
-- Alone in the Dark (1993) -- survival horror forefather; mixed polygons and 2D prerendering
-- Resident Evil (1996) -- popularized survival horror genre
Music - 2
-- Dance Dance Revolution (1998) -- increased profile of music games; spawned global phenomena
-- Guitar Hero (2005) -- popularized player use of pseudo-instrumentation in music games
FACTS
Games from the '60s: 1
Games from the '70s: 7
Games from the '80s: 31
Games from the '90s: 51
Games from the '00s: 10
Most Featured Developers:
-- Nintendo (12)
-- Konami (5)
-- Sega (4)
-- LucasArts (4)
-- id (4)
-- Looking Glass Studios (3)
-- DMA Design/Rockstar North (3)
-- Origin Systems (3)
-- Taito (3)
-- Valve (3)
-- Namco (3)
-- Capcom (3)
-- Sierra (2)
-- Blizzard (2)
-- Activision (2)
-- Maxis (2)
-- Westwood (2)
-- Atari (2)
-- MicroProse (2)
