The AMD 790 X / GX / FX chipsets are excellent ones especially when you're overclocking your CPU. However, when you're trying to stay at about 500 bucks for a decent system, the 790 series does become a trifle expensive. Here's what I would suggest at your budget: AMD Athlon II X2 240 Regor 2.8GHz - $56.99 ASRock M3A770DE AM3 - $59.99 BFG Tech GS-550 550W - $49.99 A-DATA Gaming Series 2 x 2GB DDR3 1333 - $91.99 XFX Radeon HD 4770 512MB - $114.99 Antec Three Hundred Illusion - $61.99 HITACHI Deskstar 7200RPM 1TB - $79.99 Sony Optiarc AD-7241S-0B - $26.99 Total - $542.92 You could save some money by going in for the HD 4770 manufactured by a brand other than XFX. Also, you could pick an HDD with lesser storage space. The above system should let you play most games at decent settings. Modern Warfare 2 should run like a charm.