BackFire
Blood. It's nature's lube
I'd suggest ATI X800 Pro, they're fairly cheap and painfully good. Should run anything you want for a good while.
Or if you want you can get the Nvidia equivilent...Geforce 6800 whatever. But since you already have ATi you might as well stick with them, since switching video cards can cause some problems on occasion.
Or, if you're really willing to blow a large chunk of money, you can get the brand new Geforce 7800, which is the best currently available, but is very expensive.
OR, you can wait a bit longer to upgrade, the 9600 is a fine card still and may be able to run future games fairly well, might as well wait for the games to come out and test them on your current card, then upgrade if you're not satisfied with the performance.