What it means: After the villain has cooked up some nefarious plot, the tactic of cueing up the evil laugh track ensues. It's creepy, sure, but is also used a lot.
Villains who have used it: The Joker, Cruella de Vil, Dr. Evil, and just about everyone who's got crazy eyes.
Why it should be retired: I'd like to see a villain celebrate in a way that isn't laughter—like, a bottle of wine, for example. (Come on, think of a drunk villain. Now THAT'S funny.)