First Person Shooter: UT2k4, Quake III, Call of Duty (original and U.O. expansion pack)
Strategy (real-time and turn-based): not played many, I’ll toss in Lara Croft: Tomb Raider Anniversary if this is the right category
Role-Playing Game: you need console games, final fantasy pwns. no nominations.
Massively-Online Multiplayer (includes online-only versions of games listed above): no nominations.
“Sandbox” (you can do whatever you want): no nominations.
Other (something that doesn’t really fit into the categories above): Full Throttle (DOS era), Black Knight (DOS era combat flight sim), Scorched Earth (DOS era)