Of course, I'm quoting Frank Miller when I say that it wasn't very good. People love his take on Stilt Man, but I'm not sure he liked the guy that much (particularly the way he treated the character). I feel Masked Matador was someone that even Marvel thought sucked so much that they killed him off and never brought him back. Others have been attempted to be redeemed. There's an issue with the Jester by Denny O'Neil that's absolutely brilliant.
The only ones Miller really gave serious treatment to were Bullseye and Gladiator. He did suggest that he wanted to do a story with Copperhead but never got around to it.
But I don't think there are really any bad characters, just badly written ones. Even the Owl has been handled great by some people since the zaniness of the silver age.