Think a minute, the 9700 is 256 bit and 8 pipelines and the 9500pro is also 8 pipeline but it is 128bit, the 9600 XT is 4 pipelines and 128 bit.
Those extra pipelines mean the 1 year older 9500 holds it's own and often beats the the 9600 clocked much higher than it is, remember the HL2 benches in Sept. ( it was the better card but it cost ATI too much to produce and was discontinued but still supported).
If you can afford the 9800pro, then do so.
Otherwise the 9700 is the best bang for the midrange buck now (I love it when prices come down).
The 9600XT does a great job but just go over to anandtech or tomshardware and check out the benchmarks that compare all the varieties, the 9700 one year later is the card to buy if it fits your budget.