These are the games that I personally went "wow...this is amazing!" with at some point whilst playing them. Consider them the benchmarks of their time.
PC:
Quake 1, 2 and 3
UT99
Splinter Cell 1
SW:KOTOR
SW: Jedi Knight Jedi Academy (Force choking people over cliffs NEVER gets old)
Shogun, Medieval 1, 2 (Total war)
Homeworld
Black & White
Mass Effect 1
Dragon age: Origins
Command & Conquer
C&C:Red Alert
Total Annihilation
Starcraft
COD 4: MW
Sid Meiers Alpha Centauri
Sid Meiers Civilization 2
Max Payne
Freelancer
Half Life 2
Console:
Metal Gear Solid (1, 2, 3 - never played 4 so :/)
GRAW 1 & 2
Gran Turismo 2 (where did my life go?!)
I don't really think much of my console games in all honesty :/
PC:
Quake 1, 2 and 3
UT99
Splinter Cell 1
SW:KOTOR
SW: Jedi Knight Jedi Academy (Force choking people over cliffs NEVER gets old)
Shogun, Medieval 1, 2 (Total war)
Homeworld
Black & White
Mass Effect 1
Dragon age: Origins
Command & Conquer
C&C:Red Alert
Total Annihilation
Starcraft
COD 4: MW
Sid Meiers Alpha Centauri
Sid Meiers Civilization 2
Max Payne
Freelancer
Half Life 2
Console:
Metal Gear Solid (1, 2, 3 - never played 4 so :/)
GRAW 1 & 2
Gran Turismo 2 (where did my life go?!)
I don't really think much of my console games in all honesty :/