[Brutus]

PC Games only, in the order that I think of them.

Team Fortress series. - Enjoy the teamwork, and the variety of style available
Stunts. - We has a sort of league going at school, we'd each create a track, then pass them round on floppy disk. to see who could set the best times on each others tracks.
Bolo. - Lunchtimes on the apple macs at school. good times/fond memorys
Starcraft. - good LAN game
Freespace. - Loved that saving or destroying capital ships in missions had a direct impact on later missions.
Allegiance. - God, almost forgot it, Scary to think I've been playing this game at least once a week for over 10 years! My life has changed so much over that time, Allegiance is probably the one thing thats remained constant.
Transport Tycoon. - Love creating large complex rail networks.
Killing Floor. - Deserves a mention, if only as my current mindless shoot-em-up game. (300 odd hours over the last 18 months.)
Defence Grid - Best Tower Defence game I've played, and I'm quite a fan of the genre.
System Shock 2 - Still play through it, probably once a year, trying out different builds/strategys.