Urban Terror. AWESOME game, and runs better on Linux than on Windows. Though you do have to turn off beryl.

Other than that:
Mupen64 and Mario Kart 64, specifically. Runs great, AWESOME party game on a big screen (at super high res of course!) with four controllers. Mortal Kombat 4, Snowboard Kids 2, Super Mario 64, Virtual Chess, Monopoly 64.

Zsnes:
Tetris
Bust a Move
Dr. Mario
Super Mario World & All Stars
Contra III

Through emulation there are TONS of great games for Linux. I like emulated console games better than native PC games most of the time anyway!

I DO wish San Andreas would run under wine with a joystick though. That would be the BOMB.