[whiskeytown]

For the PC

Myst
Civilization (either the series or whatever - I think you could make a case for the first for how it did, and the last for all the improvements, but really the whole series.
Tie Fighter - a Lucasfilm game that finally created an experience similar to the Star Wars dogfights that felt realistic. X-wing was pretty clunky, IMHO to be considered the best.

For the arcade

Battlezone
Pong
Donkey Kong

for Atari 2600...

Raiders of the Lost Ark - the first "quest" type game I ever played that was DIFFICULT - (similar to Myst, where you travel seeking the ark) - took me a MONTH to figure out how to beat it and sneak it's secrets out...
Combat
Poker Plus - (a 4 game cartridge that had 5 card stud, poker solitaire, and something else - that's where I learned how to read poker hands at 6 years old - [img]/images/graemlins/grin.gif[/img]

so it's the most important game I ever had....LOL

RB