Most of the Wolfenstein games work on Linux - The ones that matter, anyway (RTCW Single and multiplayer, and Enemy Territory). They’re a bit old, but they’re still great games.
Some games work nicely in Wine too, but sometimes that can turn out to be a bit of a hassle.
But my friend recently built a new PC which would be literally unstoppable should it be running Ubuntu, but he told me that he plans to eventually use Vista. Whether or not he pays for it is none of my business, but the fact is, he says he will use Vista because Direct X 10 won’t run on XP.
I don’t know if that’s true, but if it is, then Microsoft seem to be “supporting” gamers that use their OS even less than the people behind some Linux distros and some of the software applications available for them. Again, if what he says is true (I haven’t actually checked, but it seems pretty feasible), then he’s forced to use Vista if he wants to play the latest games. Forced.