Here is one reference you may use to help you:
http://www.anandtech.com/bench/Product/542?vs=647From my knowledge though, there is no definitive, all-inclusive, simple solution to your question. And when you get into SLI, most reviews don't cover that much. Forums are better, but involve a lot of searching and arguing and fanboys. I believe one effective way to go is to really figure out what you want to do (what games at what resolution and settings). That will allow you to know what GPU you desire. From there, your budget will dictate whether you can get there or not
