I have two, both dealing with mafia type things.
The first is one I have never heard discussed before, but it’s pretty good: Amongst Friends. It’s gripping, enthralling, and over-all realistic. More realistic than most mafia movies I have seen, it follows close friends who grow up together who weave in and out of the mafia lifestyle. Of course, I haven’t seen “Mean Streets” just yet, but this movie would still be solid if it ripped off some elements from Scorsese.
Also, a great early role by Mira Sorvino.
The second, one I bet people have seen before on here, is Things to Do In Denver When You’re Dead. It’s a lot more popular than the above, but I bet in a lot of circles it is still labeled as “unknown”.
This is another amazingly realistic mafia movie. Sure, some elements are pure Hollywood, but that is going to happen with a film of this type.
The best parts, for me, were the relationship, the dialouge, and the characters. With this film, there isn’t some tacked-on B-subplot of how Jimmy gets a girl - it is played perfectly, highlighting everything wrong with Jimmy’s lifestyle and Jimmy himself. It also makes the ending all-the-more tragic.
The dialouge was simply amazing. Not quite Pulp Fiction, but it was more than solid in a lot of parts. Things like, “I am Godzilla! You are Japan!” pop up throughout, just charming gems that should have mass cult appeal.
Finally, the characters. Critical Bill, Easy Wind, Jimmy the Saint- the characters are all incredibly realistic at being larger than life. Every character is developed perfectly, with not too much or too little background info given. It also has a young Steve Buscemi as the creepy-as-hell “Mister Shh” who never talks, only assasinates, and Christopher Walken, “The Man With a Plan.” Those are both actual character titles, and it fits beautifully within the film.
I’ll also second Buffalo '66, one my top 50 movies of all time, most likely.