We love our bad-guys. We need them. Without the antagonist, the plot is lost. It's easy to think of the villain as just this nameless, evil monster doing who-knows-what to the hero/heroine. Being bad is his job, right? But that's not all they are. They're (or perhaps, were) a well-rounded person at one point--with fears, hopes, dreams, ideas, a home-life, perhaps a wife, and then...something happened.
Maybe, he turned his back on the society that turned against him; perhaps, he had an injury to his brain. Or ...
Well, you get the idea. Whatever made the villain the VILLAIN is what also makes him--even if you're writing some fantasy story--"human."
I'm exploring the human side behind the mask of my villain. Turns out, there's more to him than just being the bad-guy of the story. He had a mom--who wasn't really his mom, but close enough--his dad is with someone else now, and "mom" still pines for the villain's father. This causes some emotional stirrings in the villain, as he really cares for mom--and sends her money when he can. Heck, he even refers to his father as an "asshole."
And this guy is a murderer! (With issues, of course.)
This, I hope, makes the character not only more "real," but also more believable and perhaps even something of a sympathetic character as well. Maybe the reader will end up liking the guy a little--even though you should despise him immensely (and most likely, you will.)
To me, this is WAY better than "Oooh, there's the spooky bad-guy! He's a monster! Ooooh!" Real is definitely an improvement over fake--and that's the last thing I want to try to pull off: fake.
The point is this: villains should be thought about. Their not just the evil force, they have reason, thought, intellect, emotion, a life, a home, a plan, and they have the taint of bad that makes them oh, so glad to be bad. If you have people cheering for the baddie, you might be doing it right. But you don't want to make them so human they lose the whole power you intended them to have. A fine line, to be sure.
I loves me some evil characters. Make 'em real. Take a little time to think about them, it's worth it.