Well, the first two games that got me thinking
Video Games Are The Best Things Ever was a coffee-table arcade machine of Pacman at a pub we once went to on holiday. This must have been about 1988.
Similar to this:
...except I think the pub owners had modified an upstanding arcade to make it
look like a standard oak pub-like table. Of course, I could be wrong, as it was one of my earliest memories.
Also the two most memorable arcade games I played during my formative gaming years were
Michael Jackson's Moonwalker and
The Simpsons Arcade. The latter I played in Spain, and remember jamming one 100 peseta coin after another in the slot. Goodness knows how much money that amounted to, but an awful lot. This must have been in 1992 at the earliest, because I remember the coins were celebrating the Olympic Games being held in Barcelona. Between my sister, brother, dad, and me, we managed to complete the whole thing.
The game that got me into srs PC gaming would probably have been
Incoming. I had been playing PC games for years beforehand, but before 1998 had never seen what a PC could really do with a graphics card. Then in 1998 my dad (a computer consultant/salesman) brought home a Pentium II PC with a Voodoo2 graphics card and a copy of
Incoming. I have never been as bowled over as much by graphics as the day I saw Incoming's crisp, smooth 3D wundergrafiks. I actually thought on that day that PCs were now capable of photorealism
In retrospect... not so much
Then a few months later I bought a copy of Half-Life, because I finally had a PC with the guts to run new and flashy games, and... I've been a PC gamer ever since.