Thanks, but no thanks. I've tried going the all-Linux route on this machine before (though with Linux Mint), and I remember being more pissed off than a rabid badger when I tried getting a few games to run using WINE. It was a decent OS for anything not gaming related, but for gaming it sucked. Native Linux titles didn't perform nearly as well as their Windows counterparts, and Windows games, run through Wine, were an absolute nightmare to get working.
That being said, I triple-boot Zorin OS 8 Gaming along with Puppy Linux and Windows XP Professional x64 SP2 on my desktop, and though I haven't tried playing any serious games under Puppy, I find Zorin works quite well for gaming, though only for native titles. I haven't bothered trying WINE with it, because that program is just a mess.
I know full well that you can customize the living hell out of the UI on virtually any Linux distro if you know what you're doing, but I don't think anyone has come up with a window manager as good as the classic theme interface for XP.
Zorin's is pretty decent once you find where you can change the settings, and oddly enough I actually LOVE Crunchbang's uber-minimalistic interface, but for getting real work done, XP has my interface of choice.