Never thought I would root for a serial killer

Even though it may be the obvious choice, Hannibal Lecter has to be the greatest monster of all time.  His character, in every sense, is a monster.  He is a cannibal, a serial killer, an animal.  He is a psychopath that gets in the head of his prey before he proceeds to eat their liver with "fava beans and a nice chianti."  The eery way that nothing but his mouth moves as he speaks is haunting.  His focused gaze and smirk are ingrained in our heads.

This, however, is not what makes him such a great monster.  It's his depth as a character.  Unlike Jason, from Friday the Thirteenth, we get to know Lecter and gain a respect for him.  We see his brilliance in psychology and his impressive drawing abilities.  He is shockingly polite and formal.  Unexpectedly, he becomes more human than monster, and we find ourselves rooting for him and fascinated by his presence.

This is what makes him so great.  No one would ever want to be in an open room with Lecter, for fear they may be eaten, but he draws people in.  His very few minutes of screen time are captivating and incredible.  The thought of who he is and what he does is terrifying, but listening to him and watching him is electrifying.