I use a raedon 8500. It does it's job well, and I am happy with it. (The price is probably pretty darn low on it now, too.)
http://www.newegg.com/app/ViewProductDesc.asp?description=14-102-386&depa=1
The Raedon 9000 is only like 45 bucks.
http://www.newegg.com/app/ViewProductDesc.asp?description=14-102-386&depa=1
The Raedon 9000 is only like 45 bucks.