Linux Gaming

Linux Games - Even Penguins like to have fun
Tux Games - The Online Store for Linux Games
Tux Racer - Open Source racing game
Flightgear - Open Source flight simulator
BZFlag - a multiplayer 3D tank battle game

Commercial Linux games
    ID Software - Quake I/II/III, Wolfenstein, Doom, Heretic
    Neverwinter Nights - client/server version available for Linux
    Unreal Tournament - UT2003 is available for Linux
    Loki Games - Loki Games no longer exists, but their games do