Adrian's Rojak Pot have thrown up their GPU Comparison Guide! it's well worth checking out.

These days, there are so many graphics card models that it has become quite impossible to keep up with the different configurations. Therefore, Max_87 decided to compile a guide of the various GPU configurations in the market, including many classics. We hope it will prove to be a useful reference. We will keep this guide updated regularly so do check back for the latest updates!