Real Time Strategy:
Command & Conquer: Red Alert 2 and it's expansion Yuri's Revenge. Although Wargame: European Escalation is proving to be quite the strategy game as well...
Turn Based Strategy:
Dai Senryaku VII: Modern Military Tactics (man, why won't they release this one as a DLC game for the 360 or PS3
? I'd play the hell out of it!)
Tetris. Nuff said.
First Person Shooter:
For multiplayer it's Battlefield 3, hands down. But for singleplayer... that's a tricky one. I suppose I'd nominate Metroid Prime, but that's honestly more of a First Person Adventure/Exploration
game, really. Guest I'll choose GoldenEye
64 then, I still remember that game fondly.
Role Playing Game:
The Mass Effect franchise, hands down. Can't wait to start playing it tonight (though I'm really hoping they release a patch to fix that issue with importing your previous character's face)! Fallout 3 would come in a close second though.
Best Racing Game:
When I have friendss over, Mario Kart. Any of them. But when alone, I prefer F-Zero GX.
Best Fighting Game:
Super Smash Bros Melee. Never played Brawl though, since I never bought the Wii.
Best Sports Game:
Never touched them, and never will.
Would you believe I never fully watched the original Indiana Jones trilogy? I gotta correct that someday.