"best is a tricky word, honestly. However, for around that price, I tend to recommend the Sapphire Vapor-X 7970 Ghz. Edition: http://www.newegg.com/Product/Product.aspx?Item=N82E16814202001&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
It's a powerful, well-cooled card from a good brand. That said, I couldn't say it was "the best", just a good card, and one that I consider good enough to use myself.