Nobody will listen to this, and the debate shall still rage, but maybe I can help halt the progress, if only for a few moments.
I feel an impartial voice is needed in this debate, someone who uses both on a regular basis, that person in this instance shall be moi.
To get one thing straight in this to begin with, by saying PC, i'm not necessarily referring to just Windows, remember Mac/Windows users, Linux exists too.
For a kickoff, both have their own strengths and weaknesses, often cancelling each other out on many points, Macs for example are generally more expensive (Unless you find some rip-off PC merchant), and what annoys me about most Mac users, not all, but most, is that they will always recommend one over the PC even if the person asking for an opinion only wants to browse the web, perhaps write a few documents and send e-mails, you don't want a £1000 machine to do that.
Conversely you get the same people doing the same thing for PC, when someone wants to do some hardcore video editing, 3D work etc, people will often say "Yeah you can get a PC for like £200 that will do all that", when in reality it won't, at least not without a fight, but it is true that you can get equivalent PC's for a fraction of the price of a Mac.
Second of all is software, Macs tend to lean towards only being paid-for software, when a lot of software on PC's, and pretty much all software for the Linux operating system, is free and open source. My main gripe about the Mac dev community, is that nobody compiles this software for the general Mac user, as a result only software by Sun or the Mozilla foundation is generally compiled for the Mac.
Third of all is games, now, i'm gonna debunk a commonly held myth, MACS CAN PLAY GAMES, but obviously not on the scale of PC's, and not with the performance that you can get from a high end gaming 'rig', but they can do it, more and more commonly now that macs have proper graphics chipsets, although they still don't have the driver hooks sorted out for a lot of things (3D acceleration being the main issue).
Fouth and probably the final argument, hardware. Now hardware is very important to a lot of people, it is to me, and a lot of people like to have control of their hardware, and that's where the Mac falls down in my eyes, yes you can upgrade your RAM and switch out some of the components, but if you truly want to upgrade you have to shell out for a brand new Mac, which might not have all the specs you want. Conversely on the PC side you have control over everything, motherboard, cpu, gpu, ram, hard drives and CMOS, everything is under your control. Although that isn't necessarily a plus point for a lot of people, it's very daunting if you have never even heard of a BIOS, so Macs can gain a point there for being much simpler to use.
Overall then it really just comes to what you want out of your system, just consider what you really need, and then make a decision on that, don't ask others because they're probably biased.