It is hard to rank graphics cards definitively as there are always new cards released that almost universally out perform the previous generations. This GTX580 is a great card made by a very solid manufacturer. I have had no issues doing gaming or rendering with it. Temps stay around where you'd expect with the stock cooler, 80s while under full load.
Overall, this is a very able card though I'm sure the 6xx series will have a few models that best it.