I've got ten reasons here (well, five – with all of 'em published in tonight's report, Ten Reasons Your Next PC will be from Apple):

1. Duality. Windows Vista won't be blocked on Intel-based Apple hardware. This means you will (in theory) be able to purchase a Mac computer and run Windows on it, just as you would a regular ol' PC. At least, Apple won't stop folks from doing so. However, current AND future “Windows” machines will not be able to run OS X. That's a big win for Apple. It's upon this first point that the rest of my list is built.
2. Style. Yes, you can trick out your PC with all sorts of neon cables and fancy case accoutrements – but there's something to be said about Apple's simplicity. No other PC manufacturer has come close to mass producing an elegant design that was equally as functional. It's the hardware, man.
3. Fun. When was the last time you downloaded something new. And I don't mean a new registry cleaner. I mean something completely and utterly new – out of the box new. Something that you just hadn't seen before (either freeware or shareware). The old “there's no software for the Mac” argument hasn't held water for a couple of years now, overturning itself with the advent of OS X. You'll now have a safety net underneath you.
4. Knowledge. Don't let platform bigotry get in the way of understanding and appreciating good technology. We all are better for knowing more, and that's something you should look forward to doing – not avoiding at all costs. Bury the hatchet if you think that this still is the Mac you first saw in 1984.
5. Equality. Pretty much anything and everything you can do in Windows, you can now do on OS X. Not everything, mind you – but in knowing that a new Apple machine (with proper software, I'd assume) will allow you to boot into Windows, any kind of OS driver issues will be further minimized. There's always Microsoft's Virtual PC, too.

There are Ten Reasons Your Next PC will be from Apple. BTW, I'm keynoting Macworld on Friday morning at 10am; I hope you can be there.