before this degenerates into a PC vs Mac flamewar, they both have their good and bad points. there is generally a larger number of games released for Windows than Mac, and the games released for Mac are generally released on Windows first, then Mac later. there are some notable exceptions like titles from id, Blizzard and other quality studios who respect and encourage the Mac as an alternate gaming platform.
it used to be that if you wanted to do anything creative you got a Mac. i believe that this was because the monitors on the Mac were fairly superior to those you would (normally) get with a PC. i think that this is because Apple doesn't fuck around when it comes to hardware. it only makes/gets made good stuff. on the PC side you're normally using whatever the hell monitor your employer wants to pay for, which is usually a shitty cheap pc/monitor. it is my solid opinion that if you shelled out the cash for a hi-quality monitor and sound card for your PC then you would have a machine that is in every way equal to the audio/visual creation task you want to perform.
nowdays i believe that the "if you want to do something creative you get a Mac" idea is mostly due to advertising, styling and brand loyalty than anything else. perhaps also because Macs are simpler to set up and use, and creative people normally aren't necessarily techy people, nor do they have the inclination to learn. they just want to plug it in and for it to work, because it's a tool. (unlike some techy people, i totally understand this mindset. i do not know how to maintain my car, for example).
so yeah, i hope that helps. i guess that the short answer could probably have been "it used to be that if you wanted to play games you'd get a PC, and if you wanted to work or learn you'd get a Mac, but now the lines are getting a little blurry ad Windows becomes more stable and more games are released on the Mac".