Just to add on to what everybody else said (I also am an Apple user):
1) I agree with waht everyone else upstairs has said. I'm using a 15" Macbook Pro and it's been wonderful the entire time. It's never crashed. Also, I'm not too much of a gamer, but it is true, there arn't
as many games for Mac, and overall, games
will run better on a PC.
One of the downsides to Apple, IMO, is the lack of diverse software. I recall (back when I had a PC), I could usually find 15 different programs to do the same obscure job. At the same time, there might be only 1 or 2 for Apple to do the same thing. At the same time, though, the programs written for Apple are expertly done, usually.
One of strengths of Apples are that they are top notch for music, pictures, and videos. In other words, if it involves any media, Apple's youre choice.
At the same time, Microsoft is youre choice for most things work-related. I cant lie...if I'm writing a big paper or something that is work-related, I'll switch back and use my old PC for a bit.
Another plus about Macs is that they are virutally immune to virus/spyware/etc. Yes, there are many reasons...but let's not start that argument now.
A well build PC will generally be more powerful then an Apple one. For me, at least, a big downside to Apple was that you
have to put it on an Apple machine. In other words, you can't legally install it on a PC, or anything that you build.
Finally (sorry, this is wayyy too long), I would reccomend (if you buy an Apple) to use BootCamp and either dual boot (use both OSs) or buy Virtual PC. This allows you to run Windows inside youre Apple.
Thanks.