9800GT (Video card)
Intel Core 2 Duo @ any Ghz u want
500G HDD ( I use Hitachi)
A nice motherboard as long as it doesn't crap out, check reviews for it.
4 Gigs of Ram--Ram is cheap so don't worry bout that--
Thats the basics, just makes sure the hardware dosn't suck i.e if its super cheap it sucks
Buy from newegg aswell they have great customer service, its where i bought my parts.