There are a few series that I can think of where the English dub is better than the sub. Black Lagoon and Cowboy Bebop come to mind.
Cowboy Bebop's MCs (except for Ed) are better in the sub imo, but the background characters are pretty good.
i don't know how but Ed in the dub actually reflects, if not exceeds the sub.
i haven't watched Black Lagoon, but the only other show where i even considered the dub was Monster. i kind of wanted a german dub but that'd be a pain in the ass to find, and the voice acting doesn't want to make me shoot myself and i actually feel like it fits more than japanese.