www.slickdeals.net is an excellent resource to look at on a daily basis for some incredible deals. Every so often theres a dual or quad core system on there for $400-500 that includes 2gb RAM, 100gb+ HD, and a crappy video card. You could buy an 8800GT and you have a system that could run 5 WoW's.

Theres a regular amount of incredible deals on monitors too, like a 22" Widescreen HD monitor for $249 and such. Search the front page and the forums.

This is all if you have some time to wait and snipe the good deals.