I've got an ATI Radeon 9800 Pro, and it works great. The drivers haven't given me any trouble at all.
Far Cry looks beautiful and is the first game to really take advantage of the DirectX9 abilities of the card. The 9800 Pro (and FX5900XT too I think) can handle many of the newer games much better than the 9600 series.
It does seem to be a little pricier than the FX5900XT cards right now though. I just read that the new generation of latest and greatest cards from both nVidia and ATI will be released in the middle of the month, so you may want to wait and see if the prices drop appreciably.
goates