I have an 8600GT right now and am looking to upgrade. I know that the Dell PSU is quite reliable and is able to run a 9600GT, but I was unsure if it could run a 9800GT, which I've heard only uses up between 8-10w more. Thanks!
I wouldn't count on the Dell 305wt PSU powering a 9600GT. Maybe brand new, for a bit, but if the Dell PSU is a couple years old, it capacitors may have started to break down, just enough so that it will just give up. The PSU that Delluser1 suggested is a good one and at a good price. I'd say go for it.