Recently, Masterpiece Theater aired a version of Charles Dickens' The Mystery of Edwin Drood. I generally like Dickens because of his fantastic characters and dark Gothic themes. I wasn't familiar with Drood, but I was pleasantly surprised by the villain of the tale. He's not an entirely unsympathetic character. He seems to feel genuine remorse for his evil actions. The viewer eventually learns his motivations, and, not to spoil the story, I'll just say they're believable. Good book characters usually aren't born bad, but if they're written well, they become unforgettable villains because something in their lives has helped to corrupt them.
Some of my favorite literary villains have some redeeming quality or remorse for their wicked ways. Here are just a few of my picks: Ebenezer Scrooge, Frankenstein's monster, Othello, Dorian Gray, Professor Snape, Richard III, and Grendel's mother--hey, as a mom, I can empathize. Who else is unforgettable?