Expand for the links!
Intel Pentium G840 CPU: http://amzn.to/uGHcWg
ASUS P8H61-M LE/CSM Motherboard: http://amzn.to/suVR3Z
Sapphire Radeon HD 6770 Graphics Card: http://amzn.to/w4oBTB
Corsair XMS3 8GB RAM: http://amzn.to/vKC1XN
Western Digital Caviar Blue 500GB Hard Drive: http://amzn.to/sVdqQZ
Thermaltake V4 Black Edition Case: http://amzn.to/tv2pDK
Cooler Master 120mm Case Fan: http://amzn.to/u5ZgwF
Cooler Master Elite 460w Power Supply: http://amzn.to/tJh6G2
Asus 24X DVD Burner: http://amzn.to/skDoFQ
Windows 7 Home Premium SP1 64-bit: http://amzn.to/sJCwgC
All prices are from Amazon.com as of 11/29/2011. Expect these to change on a very frequent basis.
In this video I give a guide on building a gaming computer for under $550 as of November 2011. With this build you should be able to handle most PC games at 1080p.