http://www.amazon.com/Boss-Bosses-The-Paul-Castellano/dp/0440212294

O'Brien and Kurins no doubt embellish some of the truth but the meat and potatoes of the story is a great read. Covers the more than two years and 600 hours of recorded conversations between Castellano and guys like Tommy Gambino, Joe N. Gallo, Jimmy Brown Failla, and Tommy Bilotti, as well as a lot of personal stuff. This is where the penile implants and the affair with Gloria Olarte originated - even though they should not have been disclosed because of their irrelevance to the case that Kurins and O'Brien were working (I believe the book got them in hot water and they had to turn over some of their profits for disclosing confidential information).