For me, on number one, I think is Salvatore "Ceasar" Maranzano. You can't find any reliable picture of him on the internet and we don't know shit about him before he came to America.
Yet he shortly became the most powerful mafia figure in New York, and was the only true "boss of bosses" the American mafia once had.
"It was between the brothers Kay -- I had nothing to do with it."
