PC (With Windows)
Pros: Easy to use, you probably already know how to use it. Easy to do more advanced stuff quicker. WAY more bang for your buck than Macs. I mean WAY more. The above person that mentioned that Macs have more bang for your buck is (not to be rude) sorely mistaken. For the price of a good Mac I could build the best PC in the neighborhood. And it would run so much faster. And you can store more information. It's not Apple's fault, it's just that there are more manufacturers for PC parts, so naturally, they are cheaper. Did I mention they were cheaper? Also, depending on your skill with PCs in general, I've found that you can just do stuff FASTER all around in Windows. Copy files, navigate through folders, move files, all that stuff.
Cons: Susceptable to virii and trojan horses and spyware and all that crap. Not sure what the big deal is though. I've never got a virus, trojan horse, or any major spyware/adware issues. Not as big of a deal as people make it out to be. Maybe it's just me. Worth mentioning: Some say PCs aren't as "stable" as Macs. I've found that it's about the same with both.
Macintosh (running Panther or something)
Pros: Easy to use interface than can be learned in weeks (or less). Simple-yet-effective operating system that makes everything streamline and hassle-free. Aesthetically, definitely top notch. Good designs here. Umm...that's about all the pros.
Cons: EXPENSIVE EXPENSIVE EXPENSIVE. I know I sound like Steve Balmer here but I mean damn, these things are expensive. It's because you can't just make a Mac. The only guys that make it is Apple. So they have to charge the dough. If everyone could make Apple parts and whole computers and all that the prices would go down. But right now they are abominably steep. And college students like me don't have that much to spend on a computer. Second issue: These things don't perform as good as an equivalently-priced PC. I don't care what the Mac fanboys say, they just don't perform as well. Why? Because they aren't as fast! Simple as that. Not as much RAM, not as much processing power, not as much hard drive space. Any other question?
The biggest con of all: If you are into advanced stuff or "interesting computing" (ask me via PM if you don't know what I'm talking about) or anything like that you are fucked. It's just the complicated stuff that Macs fall short on. The shit I pull with my PC is light years ahead of what I can do with a Mac. If you are into editting movies and running Photoshop and typing papers and surfing the web, get a Mac. If you are going to do things that aren't always legal (but of course not necessarily illegal, mods) then maybe a PC is the better route. I'll explain in detail, like I said, via PM if you want. That's my two cents