The Essence of Evil
I need to read that.
What was he basically like?
I didn't read the whole thing, but one of the pieces I read was Satan's Soliloquey. It was beautiful! The whole story is based on Satan's side of the story. It's not supposed to make you pity him. He's still supposed to be evil, but it's hard not to think of him as the hero of the novel. It raised a lot of hell (hah.) when it was published because people thought it was blasphemous.
Anyway, Satan knows he's bad and wishes he could return to Heaven, but he also knows he can't because he is too power-hungry and would only try and reenact his revolt against God if given the chance to return. It's really interesting the way he reasons with himself. I definately recommend it.