Do you want to know the Bad Guy’s motivation in a story? It helps from a writing perspective to understand an antagonist’s background, even if all the reader ever sees is a classic villain, existing only to make the hero’s life a nightmare. Frankly I think learning a bit of the villain’s history adds depth to the story, for the reader. We all knew some of Voldemort’s background, it hardly made him more sympathetic; in fact it made him worse. Didn’t our hero, Harry, overcome a similar past, without becoming evil?
Dare I admit publicly that I not only enjoyed reading Twilight I thought that turning a classic bad guy, good, was positively refreshing. Everyone luvs a guy who could be bad, but won’t. (Chocolate, to the first one to identify that sorta quote.) Then the villain in that story ended up being a vampire who did embrace his dark side. Someone should write a story about a classic good guy gone bad… hmmmm, like an ANGEL! Wait, I think I read that book. Oh my gosh, it’s a true story too. Well, I don’t think we’re gonna top that bestseller.
Then there are villains who, with a dying breath, repent – aka Darth Vader – gotta love those. How about those unfeeling villains, where resistance is futile as in the Borg? Terminator? You’re not going to sway them (well, except that one episode in TNG/and the second terminator movie – but other than those).
How about those Villains you love to hate? Jane Eyre’s Aunt, cousins, everyone who ran the Lowood School; Captain Bligh – and he got away with it, which just makes it even worse (or better if you were the writer); Cruella DeVil; All Evil Step-Mothers/Sisters/Cats and Uncle Scar in The Lion King. How about you, are there any evil geniuses you’re still holding a grudge against?
My favorite villain off-hand would have to be Professor Moriarty. Why? Because he was apparently modeled, at least physically, after a teacher that Sir Arthur Conan Doyle had, and at that same school there were two boys named Moriarty. Coincidence? But of course! Those things happen, and I just happen to delight in them.