In NYC, The Genovese Family has traditionally been the largest in terms of numbers for most of that time period. They get my vote for most powerful.
The Gambino family superseded the Genovese family in numbers in the 1970s and 1980s. And some say that the D'Aquila/Mineo/Gambino family was always the largest family.
"It was between the brothers Kay -- I had nothing to do with it."
