7. Calendar Man
Julian Day first made his appearance in Detective Comics #259 (Sept. 1958). As Calendar Man, he commits crimes based on calendar related events. It was first the seasons, and after that was days of the week. During The Long Halloween story, he acted as a Hannibal Lecter type character, as he helped Batman solve the mystery of the killer known as Holiday. Today, this is what he is best known for. Outside of Long Halloween, Day was also one of the first villains who put an effort into killing the second Robin, Jason Todd. That honour would of course go to The Joker during the "Death In The Family" arc. Calendar Man's plans were to use Todd as Batman's Achilles heel. By murdering Robin, he hoped it would lead to Batman's killing blow. However, his plans were foiled when Jason defeated Jason himself.
Ideal Casting: The obvious route to go would be to say that the bald Bryan Cranston should do nicely, and he would. That wouldn't be fun though. What would be fun is to suggest another Burn Notice-r. I don't care if you shave his head or not, but Garret Dillahunt (Who was also a major player on The Sarah Connor Chronicles), would be the perfect choice for Calendar Man. That light, childish voice, with his natural sadistic grin? He has always gone a long way with television audiences.