Im going to try not to fan boy you one way or the other.
Pc-cheaper, more brands to chose from, more options, wider base of programs, games, and software in general. cons, because of the competition and lower prices of a pc, the parts are made cheap and arent durable over time. overall quality suffers and longevity of your machine is lower.
Mac-nice,clean,rock solid os (not invincible though), super fast shipping, better quality. Used in professional settings, like game studios for maya and other high end software.
cons-expensive as crap. lower software library. Not so friendly when it comes to modifying things or emulators and the such.
Now im going to be bias, cause a friend always liked to point out that he payed a grand for hes ASUS and i payed three for my macbook pro, and he claimed his was a better deal. I agreed to a point, His played games like fallout 3 and such. His was also flimsy plastic, looked like a toy, and the screen was a lower res. Then he left in on in his backpack and it melted his motherboard. HA.
Honestly its up to you. mess with stuff and see what you like. I like both an i will use both. Mac and pc are both computers. Just different stuff.
And Duel Boot works wonders. However, my XP side is acting up atm.