Speer Gold Dot is by far the best, from all of the tests that I've seen. It's not the best in every test, but it consistently performs well.
That said, I carry 124gr. Goldensabers in my Sigs because I got a ton of it for $10/box on sale a while ago, which is half as much as I can find Gold Dot for.
I wouldn't use anything but Goldensaber, Ranger T, or Gold Dots.