GTX280... mmm nice card. Mostly a late 9000 series or GTX280 and above. I wouldnt recommend the 9000 series too much actually. I have had a fair few problems with them, and they dont offer much more performance than the 8000 series.
That is of course, if you have the budget. I had a 8800GT for ages, and I loved it. My card had a fan defect though :/ so I had to get rid of it