All of them. We may reconsider this as their drivers gotten better, but performance is still not great, especially for stuff like LCD AA text which is rendered with pixel shader. If we were to enable it, it would only be for the latest hw.
Well I had x3100 with latest drivers it played games fine, it played COD 4 ok. There drivers are getting better.
I now have a x4500HD, which I had no trouble with. Plays COD4 and Left 4 Dead all fine. I know I'm comparing with games, which isn't totally right. But I hope you do look into the newer hardware at least.