Mac has a more user-friendly interface, less bugs, and less viruses have been scripted for it. Good for beginners. Which is why they're common in schools. They're also expensive. PC's are cheap, buggy, complicated, and eventually end up virus-ridden. My kind of computer.
On the other hand, PCs support more software than Macs because of their high popularity. You can get software/hardware for them anywhere, whereas Macs actually have specialized stores for them. There's a Mac store on the Kstate campus, I love it. If you're a gamer, Macs don't even compare, due to the fact that PC's actually, in my opinion, are higher on the performance end. With the development of Windows Vista, no one in their right mind would even CONSIDER getting a Mac for gaming.
But seeing as while I've gone through about 4 or 5 pc's while my Mac-loving relatives still have the first ones they bought, some over 8 years ago, as far as quality over time is concerned, Bill Gates can kiss my
In my personal opinion, Mac is better, but given the amount of gaming I do, I'm condemned to buy Windows forever.