OS Change?

Hay guys,
I'm looking to change from Windows XP over to a different OS, and I was wondering what OS's you guys would recomend. A couple of requirements would be:
-As stable as possible.
-Able to be somewhat easy to use until I figure my way around.
-Able to be customizable once I -do- figure my way around.
-Able to run Windows OS games and software easily.
-NOT A MAC.

Thoughts?

a lot of people will tell you me is unstable but if it is setup properly it is the most stable 9x OS out there.  just disable system restore, get all the updates (directx9, net framework 1.1/2.0, etc., ie 6 but still use firefox/thunderbird) and you will be fine.  if all you want to do is games it ought to be ok and it will be slightly faster (but never as secure) than winxp.

failing that, try windows 2000 or nt workstation