The honor (or dishonor) of worst Mob movie goes to "The Valachi Papers" (starring Charles Bronson). The acting was terrible and it was almost funny to see all the "mistakes" shown in the movie (like 1960's cars in a scene that was supposed to take place in the 1920s).
Geez,I forgot all about that one,thank you for allowing me to relive the horror of that little opus. I'm off to see Dr.Melfi now to block the memory.
