Obviously, the Godfather is the best. I also enjoyed Omerta, the Last Don, the Sicilian, and the Fourth K. 4th K was not a mob book, but I found it very enjoyable anyway. I didn't really like Fortunate Pilgram as much, but I guess you don't have to like all his books. I'm a huge Tom Clancy, Patricia Cornwell, and Jack Higgins fan and I don't always like ALL of their books either.