Steven Spielberg's 1975 classic Jaws is a movie about a killer shark, obviously. On the other hand, it's also a movie about a town in crisis, as a beach community that depends on tourism struggles to figure out how to bring people back to their beaches and keep them safe after a series of very public shark attacks. This aspect comes to a head in a scene where all the town leaders are meeting and everyone is talking at once. Then the teeth-grinding sound of fingernails on a chalkboard shuts everyone up.
Those nails are seen scraping over a drawing of a shark eating a man, before the hand is revealed to belong to Quint (Robert Shaw), a tough fisherman who promises he can kill the shark, but wants $10,000 to do it. Quint enters the movie very late, but this scene quickly makes clear what sort of man he is. He's extremely competent, and he knows it, but he's also disinterested in polite social norms. He's not the guy anyone wants to work with, but he's the guy who can kill a giant shark.
Jaws is a classic film by any standard, and this character introduction is one of the all-time greats. On the other hand, every other choice on this list, new or old, can stand alongside it. When a character's introduction is memorable, you remember them—and when you remember a character, you remember the film that contains them. That's why every film on this list is in some sense a classic, and every character—good or evil—is beloved by their fans.