Comparative Performance of CUDA Cards

The question in my mind at the moment is “which Nvidia card is the best value for money for SETI?”. I have gone through the results from the CUDA work-units and pulled out the ones where the credit granted is the credit claimed (i.e. work units where both computers used GPU).
I have used my machine as a reference with its 8600GT card with 256M RAM. The potential problem is that I am running the Crunch3r CUDA client on 64-bit Linux and every other result came from Windows machines. This may account for he big difference between my GPU and the next slowest on this list which is a 8800GT...?

In this table, the speed of the GPU cards are the number of identical work units they could process in the time taken for the 8600GT to do a single work unit.

8600GT(256) Linux : 1
8800GT (512) : 21.3
9600GT (512) : 25.3
9800GTX (512) : 23.1
GTX260 (896) : 17.0
GTX285 (1024) : 24.2
GTX295 (896) : 23.2

Out of that lot, the 9600GT seems to be the first choice! I will spend a bit more time on this and post a more comprehensive list as I get more data.