I gotta jump on the bandwagon here and agree. If you want to play games with really good graphics and performance, a PC is the way to go. As others have stated, you can get a high performance PC with a high-def display for right around the same price as an entry-level Mac. (BenQ Monitors, XL Series, RL Series, Gaming Monitors at TigerDirect.com
Macs are good if you've bought into the Apple ecosystem (iPhone, Apple TV, etc.) and you're mostly going to be editing music, pictures, movies, etc.