MAC OSX = Pretty user interface but not a lot of applications compared to Linux or Windows.
Linux = Gnome and KDE desktop environments (Which I don't think look very, very nice) and have a lot of Open-Source applications that can rival many freeware and even paid applications that are available for Windows.
Windows = The User Interface is nice and there are applications like Rainmeter that can make it look even nicer. The are a whole slew of applications for Windows because it controls so much of the market share.
