5) Joe Pesci
Goodfellas and Casino are two of the most profanity-laden movies of all time, and while they share a handful of actors, the most crucial person to appear in both films—in terms of both the quantity and quality of the curse words—is Joe Pesci. Casino uses the word “fuck” frequently and effectively. The movie is all about these crooked mobsters who are duping people into thinking they’re straight businessmen, and the moment Pesci’s character breaks out the word is like he’s coming out as a gangster to the weak schmucks he’s lost patience with.
Most of all, and this is on display throughout Goodfellas, he uses curse words as a way of coloring his speech with a certain texture and rhythm, as a character who can talk and talk and talk but is always just on the edge between idle talk and horrifically violent outbursts. Basically any time he dons the hairpiece, beware Joe Pesci.