I would totally do that but I have last years 27inch iMac because I prefer to work a lot in my spare time and therefore a Mac is just superior for graphical working.
Most publishers only release games for the PC tho (Blizz I love you for SC2, WoW and soon Diablo3 on the Mac). Before anyone asks: I play WoW on ultra settings (even shadows) with 60 FPS in raids so no Macs are not crappy for gaming !!