C&C (Tiberium Series) [Especially C&C 3, I love those cut scenes]- RTS
Battlefield 2 (2142 is cool and all but jihad jeeps in that game just feels wrong)- FPS
Baldur's Gate: Shadows of Amn(Neverwinter nights is pretty good too)[WoW = Internet cocaine = Bad for your health]- RPG
Garry's Mod- Sandbox (is that really even a real game genre)
MechWarrior 4 ( and its expansions) [Well FL would be second but since you can't use a joystick to fly thats why it isn't first]- Simulator
Commandos- other
Is there any games I forgot? Well If I could remember them they would be good.
(Total Annihilation is pretty good along with Starcraft however, it is because of WoW there is no SC2 since Blizzard is making a @$$ load of money off of WoW and Burning Crusade)