the 8800gts is wayyyyy better than the 9600gt. the $200 9600gt has 1gb of ram instead of 512mb... big deal, not enough reason to bump the price up $30-60. the 8800gts outperforms the 9600 by a mile
the 9800gtx is a little bit better than the 8800gts but not by much at all, maybe 5-15 fps in games and it might run a little cooler. i would still go with the 8800gts its an awesome card