If your looking for games that will make good use of that Open GL support you worked so hard to get. The standard FPS come to mind, Quake3, UT2k4, America's Army, and of course Enemy Territory.
For a more unique game, check out crack attack (Tetris Attack open source, in OpenGL on linux) http://aluminumangel.org/attack
There is a really cool combat flight sim that I keep finding myself playing when I should be working. It's called GL-117 you can find it here http://www.heptargon.de/gl-117/gl-117.html
Also you can't deny GL-Tron/Armagetron for some old school action in a new 3d world http://www.gltron.org/ http://armagetron.sourceforge.net/
And while I have to first hand experience I hear good things about NeverBall which is ssupposed to be a clone of the Sega Game super monkey ball which came out for the GameCube a few years ago. http://icculus.org/neverball/