I thought I posted my own opinion too, but hey..

I'd choose Gambino, because all of it's leaders got their top positions by killing the former one (except for Castellano, who had to wait for his Don to die).

The Castellano reign to me is the most interesting, not because the guy himself was so cool, but more because he control and at the same time was threatened by two dangerous crews, the Roy DeMeo crew and the John Gotti. Old Paul Castellano managed to get rid of DeMeo just in time, but after Neil Dellacrocce (the underboss) dying there was no stopping John Gotti. Gotti made his bones in the Castellano era (maybe even earlier) but sure didn't when he was the leader himself. The Castellano period I like most, but not for the leader.

My favorite leader is Luciano too, for setting up both Masseria as Maranzano, two rival kings. Brilliant!

I loved your joke btw BronxKing