1. Hannibal Lecter - Silence of the Lambs, Red Dragon etc
A brilliant psychiatrist who gets right under your skin and also a cannibalistic serial killer, Dr Hannibal Lecter is up there with the top psychos on the list. After being caught cannibalising his victims, he is jailed. But he is such a great shrink and mastermind serial killer, the police have to pick his brains in order to get into the psychopathology of two killers - Buffalo Bill and The Tooth Fairy. Lecter likes to play games and masterfully manipulates everyone around him. He manages to evade prison security and escape to Italy where he carries on with his capers. Hannibal Lecter is a true dyed in the wool psycho. He doesn't give a damn about people. They are either there to kill and eat or else play head games with. He is also very vicious and might take a chunk out of your face if you get too close to him (this is why he sports a mask and is trussed up like a turkey in the films). His awesome intelligence and cunning are part of what makes him so psycho. Getting one over on Lecter is a hard, hard hurdle to jump and that's what makes him the greatest screen psycho.