That GPU Boss site seems good in theory, until you try and compare older card to newer budget cards and they have massive amounts of missing test info.
Also it's a bit off-putting that you can't see the bench comparisons of more than 2 cards at a time. On top of that, you don't see where they get their comparison #s. Are these at 1680x1050? 1920x1080? AA on? MS or FX? AFx16 or off? What are the specs of the test beds for comparison?
I'm sure they have the info somewhere, but clicking around I couldn't unlock it.
I'll stick to
Anandtech's GPU Comparison site for the meantime.
EDIT: To their credit though, I do like how GPU Boss allows brand comparison beyond reference cards.