I have XP and had Windows 7 on my Mac through bootcamp and I run into a lot more problems with them then on Leopard. I also have XP on 2 laptops and a desktop and Vista on another laptop and desktop, and my Leopard is still the best out of all of them. Vista is just balls and then XP on the rest, when it’s fresh it’s good but then it just seems to get slower and slower and then things stop working and I have to eventually reinstall it cause it’s just easier that way.
I also have Kubuntu on my PS3 and I had it once on my Mac, and yea it was awesome cause it’s just like Mac as they both run off of Unix (far better) and it’s free but I think after setting it up and stuff, I think Linux is too much for the average computer user. It’s highly configurable but you have to know how.