Honestly I think Windows 7 is the best yet but that's me. I've been using Apple since 10.4.11 (I won't go into the details of how but yeah, it's pretty obvious) and I hate to say it but Lion has been kind of a letdown for me. It's just too damn gimmicky for my taste. Leopard, Snow Leopard, then Lion. They just get sillier but I have to have Lion for Fermi support so I'm stuck. I boot into Win 7 99% of the time.