Windows XP Media Center. Also, I love 98 SE and 95 because I've never had an issue with them. Tryed Vista for like 2 days and the pissed me off with continuous bugs etc. Thank god I was given the OS as a present.
I loved Win95 because it let me get my feet wet and learn about PCs and it was really pretty simple, but I like XP now because it's actually reliable!
Tom
I've been with Windows from day one and XP has to be the best purely from the view of reliability. Windows v3 blew me away with it's GUI but again it had problems abound.