Personally, I think mob movies are incredibly damaging to American Culture. Every time a new mob movie comes out, a couple of thousand more impressionable guido kids think they're invulnerable wise guys. The result: a spike in bar brawls and stupid petty crime, and more irritation to social critics like myself.
That being said, I gotta go with The Untouchables
(Just to head snide Euros of at the pass, I know 'American Culture' may seem like an oxymoron
"Sympathy is something that shouldn't be bestowed on the Yankees. Apparently it angers them." - Bob Feller