In the most general case, I'd say A2 has performed the best for me. If we're talking stainless, S90V is probably the best I've had, though I'd be curious to see ZDP-189 in a lower RC than I've had to stop some of the microchipping and because, well, who doesn't think it's a pain in the ass to sharpen? VG-10 is a solid performer with a crazy sharp edge that's quick and easy to get, and it hasn't faced the heat treatment problems S30V has had, but I've had a lot of rust problems with it, which is somewhat surprising given the overwhelmingly-positive reviews I've seen. All in all, though, I love H1. I'm a no-muss-no-fuss type of guy, and a no-rust steel that can hold an edge better than Ti gets me wet.
But enoughf about me; what's youre favourite steal?