Without going back too far:

Red Faction (1) - FPS
Aliens vs Predator 2 - FPS
Freespace 2 - Space Combat (FREE NOWADAYS!)
Freelancer - "Open" Space Combat
Psychonauts - Jump'n'Run I guess
Homeworld - RTS
Ground Control - RTS
Spellforce 1 or 2 - RTS / RPG mix
Grandia II - RPG
Vampire - The Masquerade - RPG
Flatout 1 or 2 - (Very fun) Racing

Enjoy your meal
Toast