I always had a mac. I even had an Apple // before I had my first mac. And now I have a G4, and I love how cool it looks and how easy it is to use. And it looks brighter than the PC and the PC has grey menus, which suck.
That being said, for me the most important thing on a computer is it's software, which gives the machine it's features and it's ease of use.
Macs were a clear choice 10 years ago, cause they were much easier to use than the PCs. Now it's not the case anymore. I think that macs are still easier than pc's, but by a small margin. And when OSX becomes a standard, you'll have to trash all of your mac knowledge cause it's Unix, not mac.
That's for the ease of use. Now for the features. It's clear than the pc will always have more features than the mac. Why? Because 90% of the programmers develop for pc. A computer is just as worth as its software. Think about the Gigasampler, and Acid. That's just in the music department. In the rest of the software the difference is much bigger.
The disadvantage is that if Windows breaks then you have to be Bill himself, and even then you don't have a clue of what's happening. But as I said, with OSX you'll have to be Linus Torvald.
I am very sad (I really am!) to say this, but I think that the PC may be a better choice these days. Apple is just one company, while PC developers are hundreds and it's easy for them to come with something new. I am pretty sure that it's even difficult for Apple to push Motorola into making new chips.
Again, I am pretty sad to admit this. Apple was a symbol that said that you could Think Different, and you didn't have to stand watching that stupid "c:>" crap. What does the hell mean, "c" is bigger than what ? But nowadays, everyone is turning into Linux, like they want to be geeks or something (I don't believe you'll ever impress girls with the ability to telnet a server: "hey look mamma, I am the root user!").
I really liked diversity, I hate the Wintel crap but now everyone is doing it... bring back my Commodore Amiga!!