could try a Nvidia 8800gts or a gtx 260 both around the same price but gtx 260 has better performance. I wouldn’t recommened going for anythign better beacuase your motherboards pci-express x16 slot is 1.0 (x8 mode) (2gb/s) bus frequency and if you bought a card along the lines of a Nividia gtx 295 or ATI Radeon 5870 your motherboards pci-express x16 controller will limit them cards.