Well, that's up for debate. Personally, I don't think they're based on any specific NY family. I don't think The Sopranos are based on the DeCavalcante's either. I think all families are to some extent based on LA Cosa Nostra families, but not one family in general.

Having said that, my favourite hit on the show is definitely the hit on Pussy. Those scenes at the boat with the Frank Sinatra music playing in the background was pure gold from David Chase.