I have to say -- all of Jerry Capeci's books are great: two are focused primarily on John Gotti (Mobstar, which was written while Gotti was still Gambino boss and uses a lot of fascinating wiretapped conversations, and Gotti: Rise and Fall, which tells the whole story), but I actually like Murder Machine the best, which is about the Roy DeMeo crew of psychotic murdering car thieves and the DeMeo/Gambino capo Nino Gaggi partnership.

Selwyn Raabs's Five Families is, to me, the bible of organized crime, tracing it from its roots to the present. You can't not read it if you are a fan of this genre. Sure, it's long, but it is so compellingly written I went right through it.

I just started reading the First Family by Mike Dash which is unique in that it focuses on the Morello Family, the first crime family in America, and focuses on the American mafia in the pre-1930 period, before the Masseria and Maranzano war which Luck Luciano stepped in and ended, then organized the mob into the Five Families we still now today (although Profaci was renamed Colombo for causing problems for other bosses).