[Caduceus]

Games are beginning (just beginning, mind) to be on Vista only, i.e. Shadowrun and Halo 2, XP still has some life in it, I'd get the XP Pro version so you can upgrade to Vista more easily (cheaply) in the future.

DirectX 10, etc will require Vista, if I am not mistaken.

And this is when the Windows haters come out of the woodwork...

But 90%+ of the world uses Windows, Vista will be required in the next few years. You can dislike that fact, but it is most likely going to happen.