Without a doubt, hands down, Salvatore Lucania aka Charles 'Lucky' Luciano..
Without him, there wouldn't be the framework there is now and the Italian mob would've gone the way of the Irish and Jewish gangs: DEAD
Smartest and only real answer. Although...
Johnny Torrio allegedly had major input into The Commission set up, along with Lansky, also set the Chicago Outfit up and was responsible for bringing Capone to Chicago.
