Between these two only, I use PC. I would consider getting OSX if and only if it was legal to install on non-macs, although I find many features and apps of OSX useless (as I don't do videos, take pictures, webcam chat, etc.) and I hate using media playlists (especially iTunes) of any kind; I'm a winamp "click to play" kind of person.

However, I use Linux Kubuntu the majority of the time, occasionally using Vista to play higher-end games, and to run a couple of programs that Wine will not adequately run at this time. Vista is not a bad OS; it just needs some work under the hood, which Microsoft is promising to do with Windows 7.