Oh, snap, we've got another PC/Mac rumble on our hands? I haven't seen one of these in months! That's it, I'm taking my gloves off!
What Sonnyboo said is 100% correct, in my opinion. Both systems work, fantastically, if you know how to use them. Arguments about which is better are nothing more than pure preference.
Me? I prefer to not spend any more money than I have to. And there is no denying that PC will get you the same thing, at way less the cost. Sorry, Mac-heads, it's true.
This is purely anecdotal, but in my experience, people who swear by Mac have really only used Mac. People who swear by PC use both, on at least a semi-regular basis. And we're experienced enough to realize that they're both quite functional, yet one is considerably less expensive than the other.
BTW -- Windows 7, 64-bit, with CS5 -- gravy!