Title Says it all for not going to upgrade to crossfire or SLI so what is the best bang for the buck it is possible that if I could get crossfire x for the same price if it would be faster I could go there.
I play Eq2 Supreme Commander 1,2 and Diablo 3 when it comes out.
all cards are in the 240 to 280 range benchmarks are all with in about 15%
I haven't played EQ2 in a while but previously 2 card set ups were near worthless for it and I am guessing it is the same now.
The GTX 560 replaces the GTX 470, so if you don't mind the inferior design of the GTX 470 and you can find one cheap then technically it will be best bang for your buck, but it is hotter and louder and more power hungry than the GTX 560.
If you are playing at 1920 x 1080 res or lower then the 6950 1gb will be better bang for your buck than the 2gb version.
My personal preference is the GTX 560 as I prefer Nvidia, but the 6950 is probably a better buy (escpecially if it can be flashed into a 6970)