It really makes a difference which versions of those cards you are comparing. A factory overclocked card of any of those types will beat any of the others at stock speeds. There are some very nice models out with aftermarket cooling and factory overclocks for all of those models. So, it would be helpful to know which exact models you are comparing.
I would recommend the GTX 460, just to get PhysX, if there is nothing else that separates them. The other cards don't have it. There are also several very popular games that significantly favor Nvidia cards, such as the Call of Duty series. Based on several forum posts, it seems that Nvidia has fewer complaints about their drivers as well.