If you don't mind ATI you could look at an HD 6870 or 6950 for 180 to 250 bucks.
http://www.newegg.com/Product/Produc...0%20-%20%24300
I've had HIS, Powercolor, Diamond and all of them have been pretty good for me.
I've got a HD 5770 and love it.
If you don't mind going upto around $320 you could get an HD 6970
http://www.newegg.com/Product/Produc...on%20HD%206970
And if you get one with Dirt 3, and if you don't like racing games, you could always, oh I don't know, send the code off to someone who helped you pick a nice video card.