I voted Bonanno. Even though mobsters had it easier in the early days when it came to law enforcement, they still had to deal with each other. Bonanno was able to take over a family at just 26 and maintain power for about 30 years. He made some blunders in the 60s, but was still wily enough to come out unscathed and retire.
SonnyBlackstein outlined in an earlier post why Massino doesn't get the vote. While he did rebuild the family, when the heat was on they all folded like a house of cards.
Apart from the big SNAFU he had with the Commission in 1964 (when he tried to become the boss of bosses by having Gambino, Lucchese and his cousin rubbed out; Genovese was in the can at the time, so he wouldn't be much of a trouble), and the tell-all book he wrote (which was used in the Commission Case) I'd say Joe Bananas was the most competent of all the family bosses. Points to note:
-Rising up the mafia ranks very quickly was a rare feat, and so is becoming boss at the age of 26.
-40+ year mob career (6-7 years as Maranzano's right-hand man, and 30+ years as boss) is very rare
-Very smart, shrewd for his age
-Even after writing a tell-all book, refusing to talk to Giuliani about this and spending 2 years in the slammer for OOJ, and not facing any retaliation from New York for his book (perhaps he was the only one of the original five bosses alive at the time) really tells me something about Bonanno
