Good dubs exist, although rare. I think the problem is that some actors don't take dubbing seriously, they just read lines and put it in a "cartoon character"'s mouth instead of actually "acting" the character.
Rather than an English dub, what I'd want to see is a German-Czecho dub and hear the names and places pronounced as they should be, even if I don't understand either language. Even better if Tenma's dubber is a German-speaking Japanese for the accent!
But perhaps it's just a dream...