acording to this article:http://www.tomshardware.co.uk/best-graphics-card,review-31783.html
the best value for $200 is the hd 4890
and the best at $250 is two gts 250s or two hd 4850s
also supposedly in less than 2 weeks (around jan 25th) the hd 5830 will come out that should be as good as a 4890 but with dx11 and stuff. priced around $200.