PC - with Windows, of course.

I don't like Mac OS X simply because there's nothing important I can't do on Windows that I can do on OS X.

Linux is still very immature as an OS. I've no sound - no drivers for the Xi-Fi. There was no visable support for RAID drives (oh, it's there, Linux recognises them in install, but in the OS itself they seem to disappear... bloody confusing) and GRUB still has a fit with them for some reason. So not only can I not access all my data, I also have to juggle the boot sequence when I want to change OS. When I actually wanted to install something, I had to install package after package after package after package after package after package after package after package after package...

Nah, it's Windows all the way for me, baby!