K get an AMD X2 3800+, and either get a 7800GT ( but if u can afford a 7800GT, u can sure get a 7900GT because its about like a few dollars difference) or get a x1800XT, its an excellent mid priced Video card, one of the best.
Get a MSI K8N NEO motherboard
Antec TruePower II 550Watt PSU ( cheaper than the Enermax im positive), one of the best power supplies out there, and its cheap
2x1GB OCZ Value Ram Dual Channel DDR ( make sure its not DDR2)
WD Raptor 36GB 10K for the system, like games and the OS and stuff like that
WD Caviar 120GB for storage, all ur files, music, and movies.
and that should be GREAT and probably adds up to about $750-900, i didnt calculate the prices but thats an estimate.