Personally, I love Windows 7 since it is pure eye candy to me. I've used Vista but eh, I have found absolutely no problems with it. I just decided to stick with my XP since I was too lazy to reinstall all my programs. I love all the OS that Windows make. But for now, Windows 7 wins it for me.
Should rephrase that, as long as any OS (OSx, Linux) can use the web/basic programs, I will be glad to use it. But Windows for games ftw.