Also, Death Collecter, otherwise known as Family Enforcer is another pretty weel done independent film from the 70's I believe, staring a young Joe Pesci and Afro infested Frank Vincent.

Then there is another independent film, Mob War, staring the actual Jake La Motta (whom Robert De Niro portrayed in Raging Bull). Its actually a pretty horrible movie, in my opinion, but you weren't asking for good Mafia flicks.