single, dual, or quad core cpu?

as for memory... you'd want 2G for up to 3 wows, 4G for 4+ wows (if you are on XP... get 4G of memory and your system will use as much as it can.. 3.5G of it)

and if you can, please get an nvidia 8800 w/ 512M of memory ... $150-200... definitely worth it
http://castle.pricewatch.com/s/search.asp?s=8800+gt