I run Ubuntu 7.10 64bit. Been using it for ah wile it runs really well and I have it so tweaked out and customized its insane. I actually have it look semi like Vista, just because I like the style. I don't have the vista start menu icon though I did at once, I now have a skull and crossbones as my icon, "Danger"....
I have used kubuntu, mythbuntu, ubuntustudio as well. I just really like the clean, crisp and easy custimizablitly of gnome, I did like KDE out of box compared to gnome but once I customize gnome it takes the cake.
I just started using "virtualbox" and have it load XP virtually, really cool adn runs really good. I hardly need to reboot to get to XP anymore, actually dont remember the last time I did. I have this setup on my desktop and laptop.