Well dude, for top performance, the mother of all existant graphic cards is going to be launched by 14th May lol : nVidia 8800 Ultra..
Anyway, as I advised in another thread, can you wait a few months? New thing are going to appear in the following months :
- Affordable Quad Cores
- New Chipsets
- Consequently, DDR3 ("new" type of RAM) supporting motherboards
- ATi Dx10 graphic cards