1) Charles A. "Pretty Boy" Floyd (One of my great-great uncles was married to one of Floyd's cousins so I had to put him first)
2) John A. Dillinger (He had style.)
3) Alvin "Creepy" Karpis (Unfortunate nickname but apparently very smart and well-read)
4) George "Machine Gun" Kelly (By all accounts, a nice man)
5) Verne Miller (A maniac but, as a former cop, he had an interesting backstory)
6) Bonnie and Clyde (They would be ranked by higher but apparently Charles Floyd hated them and there's something to be said for family loyalty.)