The Quake Series

Quake
DarkPlaces
We've been playing Quake on the DarkPlaces engine as opposed to the original version for a few reasons:
- It runs on Linux, OSX, or Windows
- The official Linux binaries provided are based off of outdated libraries.
- It allows you to play in OpenGL even without one of those old Voodoo cards
- It allows you to back up the soundtrack in ogg format so you don't have to have the CD in to play music
- It has much more modern graphics (It stresses DrunkenHeinz's Linux box with a 512 MB 8x AGP nVidia card down to ~30 fps, but it's possible to run it on the old Pentium 3 we use by tweaking the video settings a bit)
- It's open source
DarkPlaces Links
These links are straight from the original developer's site:

Quake II
We're not playing the second quake yet because of shady support under Linux. DrunkenHeinz almost has it working, but no/shady sound/fullscreen support. Will be worked out soon.

Quake III
Quake III Arena and Team Arena work almost straight off of the installer from id's website. The only problem is that it doesn't want to use a reasonable sound driver by default. We use a hack (et-sdl-sound) that works for Return to Castle Wolfenstein, Quake III, and Return to Castle Wolfenstein: Enemy Territory. The hack enables ALSA support through SDL.

Quake 4
Quake 4 runs awesome from a default Linux install.

Enemy Territory: Quake Wars
Don't know for sure that it works on Linux yet, because I haven't had the money. We'll see soon.