I agree, Turnbull. It is a tough call. Thats why I made the post. I thought it would be a challenging question for our members.

As you mentioned, Carlo did live a bit longer, so there's that. I also think we have to consider in his later years, Gambino was generally looked upon -- although technically there was no such title -- as the so-called "Boss of all Bosses" and widely acknowledged as the most senior and powerful 'Don' of the New York's Mafia, which by extension, made him the most powerful boss in the country.

That said, its still a tough choice because these two men were both very successful and underworld icons during their time in power.