Honestly, I've not used a Mac often enough to say I prefer one to the other. Of course, Windows has some very severe limitations and inconsistencies, but I'm sure the Mac OS isn't perfect either. Still, most graphic designers I know prefer the Mac and tons of teachers still prefer the Mac - I think because schools initially bought Macs and didn't switch to Windows until more recently, so they're more used to the system. I think it depends a lot on what you first learned on. I first learned on CP/M which is a dinosaur, then DOS, then Windows. Never spent much time on a Mac as they were always out of my price range and everyone I knew had Windows. If you're a Mac fanatic, what makes it so much better, in your opinion?