I'm an agnostic in the Mac vs. PC divide; I have both. Here's the main differences as I see it:
Mac
+ simple, seamless user experience
+ generally less security problems
- you pay a premium for equivalent computing power
PC
+ wider variety of sizes, configurations, price points
+ more configurable (at least I think so)
+ generally wider selection of software, free and otherwise
- you have to be your own system administrator especially for security and updates; even though I know how, it can get a little tedious.
My current laptop is a MacBook Pro. It did cost a little more; on the other hand, it just works. I might go for one of those solid state storage ones next time around.
I just got my son one of those Acer Aspire laptops with a touch screen and he's really happy with it.