Miller's Crossing (1990) by Joel and Ethan Coenhttp://www.imdb.com/title/tt0100150/
Though I am a fan of The Untouchables, this is where I satisfy my prohibition era jollies. It's a tight, contained 1930's gangster movie with more visual style and over the top awesome dialogue than I thought possible in a single film.
So I like it. A lot.
Reason people don't generally know about it is that it was released the week after GOODFELLAS! I don't think even Avatar would have liked to tangle with Goodfellas back in 1990. I die a little bit inside when I think about Miller's Crossing and its unfortunate release date.
But, because there is a God, the Coens were allowed to continue making movies despite the terrible box office showing.
So go out and buy it. It's not a rental, it's a definite purchase. Get the blu-ray if you swing with the hi-defers. Just watch it and watch it soon.