I think that the word "entranced" might be a bit strong, but I get the basic idea. There might be a penchant for films about organized crime for a couple of reasons. Part of the reason might be a simple form of escapism. For the average American that has a traditional job, follows the rules, waits for their turn, two hours of watching a group of people make up their own rules and break the established norms of behavior could serve as an outlet. Certainly, the popularity of gangster films in the 1930s fed this need for a public that was fundamentally challenged by the Great Depression. Another element that might explain the fascination could be a sense of voyeurism. The vast majority of Americans will not have to deal with the reality of mafia life. To see it for two hours could be a peering into a world they will never enter. Another reason might simply be due to the fact that some of the best films made are, in fact, films about the mob. Films like Goodfellas, The Godfather Part I, The Godfather Part II, Casino, Scarface, Atlantic City, Donnie Brasco, Snatch, or Mean Streets are examples by some of great filmmaking. With such an array of films, the genre has become seen as the home of very strong films and this has helped to increase the fascination with it.