For me the 1st reason I've bought a MAC it's the simple fact that
With a MAC you got two computers in ONE as you can run windows & OS X on the same computer. (I'm currently running Windows 7 and OS X on the same session)
2sc main reason is the software & assistance coming with.
After it's a lot of things like the long battery, the aluminium look, light keyboard, multi touch trackpad, screen.
When you close the Laptop he go's immediately to sleep (Hard drive & everything)
Compared to my old PC a Sony VAIO, the MAC is much faster also!
After I think you got some advantage using a PC as you can have some using a MAC.
The main fault I will claim on the MAC (but it's maybe only because I'm a new mac user ) is I found the PC a bit more easier to use.
For me PC or MAC is like IPhone or BlackBerry an endless discussion
Best regards.
PS