O villain, villain, smiling, damned villain!
My tables - meet it is I set it down
That one may smile and smile and be a villain.
Without a doubt the best villains are the ones that are such fully-formed complex characters, it's not hard to imagine them as the protagonist in their own story. Motivation is a big factor in this: is the villain evil just for the sake of being evil, or is there something more interesting going on underneath the surface? Something that makes you understand why the villain is doing all these villainous things, even if you don't agree with their actions.
Here's a kind of sideways example:
Laertes is a young man who sees his family destroyed. His sister Ophelia is treated horribly by her suitor, a man who seems to toy with her affections before ultimately rejecting her. Then that same man murders their father Polonius. It's a case of mistaken identity, but the killer shows no remorse. Worst of all, Ophelia is driven mad by grief and heartbreak from these events, taking her own life. When offered a chance at revenge, Laertes of course accepts. In the end, though, both Laertes and the man who destroyed his family, a prince named Hamlet, die by a poisoned sword.
But the play's not called Laertes, is it? I called this a sideways example because while Laertes wasn’t a villain in Shakespeare's play, I do think it's a good example of how one person's protagonist is another person's villain. Meaning Hamlet, of course. I used to have kind of a thing for Hamlet. Not a literary crush, exactly, more like a mild obsession. I saw him as this punk slacker who couldn’t live up to his destiny, and consequently was relieved to greet death. This eventually transformed into a mild obsession with Kurt Cobain, but that's a different topic. It's been a number of years since I read the entire play instead of leafing through the pages that mark my favorite quotes. My favorite line will always be this:
In my heart there was a kind of fighting that would not let me sleep.
There's another one that I have found myself looking at frequently. It fits with the sideways view of the melancholy prince as a mad villain.
Tis now the very witching time of night,
When churchyards yawn and hell itself breathes out
Contagion to this world. Now I could drink hot blood
And do such bitter business as the day
Would quake to look on.
Dare I say it - Vampire Hamlet?