For me its defiantly Carmine Persico his war with Joey gallo and him surviving murder attempt after murder attemp even the way he got put away for life in the big commision case hes been involved in a lot of lcn history.I wonder how things would of gone if he was aquitted and he was on the streets during the 3rd colombo war.

Also chin probably has 10x the amount of blood on his hands but his crimes and past are a big mystery