I use Mac OS X Leopard (10.5), because I need to use Final Cut for school (or so I was told when I bought the computer - still haven't touched Final Cut).

I also have Windows 7 installed via Boot Camp, which I like very much, and use for anything I can't use OS X for.

I don't really take a side. I like OS X a lot, it's very easy to use, but it doesn't have the wide range of programs/applications for it that Windows does. If I could do everything I can do in Windows on OS X, I would.

But Windows 7 is pretty awesome ...