I originally wanted a 7600GT, then an 8600GT, then an 8800GS...bided my time, saved my pennies, and got a 9600GT and was completely blown away. Compared to the 8800GS, it has a faster core, shader, and memory clock, and has almost 20 GB/s more memory bandwidth.
Either card would've been better than what I had (I was running integrated...eegh), but I'm just shocked by the 9600GT's performance in everything I do and I highly recommend you bide your time to get it like I did.