There were many shooters mentioned, but I'll only link Sauerbraten, since I played it for an hour today. The sequel and successor to Cube (an indie free 3d engine / shooter game) Sauerbraten also includes a simple single player campaign that is probably responsible for the stiffness in my mouse hand today.
Shooters are boring. Real-time strategy (Command and Conquer, Warcraft 1-3, Starcraft, Dune 2 and sequels ...) games can be lots more interesting. Glest is a new RTS, mostly for windows btu also ported to Linux, written in C++ and GL. Its two factions are Magic and Technology and it's pretty nice looking. I only played a few minutes into the tutorial (in XP / Parallels / Coherence ) but it has campaign play and scenarios, as well as multiplayer. Glest home
There is a classic RTS I didn't mention before, because I've never played it. Most recently the creator went on to make Total Annihilation a modern graphics card squeezing RTS that I hear is fantastic, but that would not run so great on my jumble of gaming box hardware. The game that made that fellow's name and career is Warzone 2100, a true classic game, and it's been freed! You can play Warzone on your box just as soon as you download it, lacking only the movies!
After all of this I can't even bring myself to yammer on about Oblivion patches and mods. Google turned up a lot of good links, and if any of it works, I will let you know. (The Unofficial Offical oblivion Path seem pretty good so far).Need game icon?