What would your examples be of movies which are representative of a particular genre or category? Not necessarily the best or your favorite, but the one that fulfills your criteria for a particular genre/type/style? For example, which movie is the most representative of "Heist Movies," or "Films Adapted from Classic Television Series," or "Mysteries with Detective Haunted By Tragic Pasts?"
I got thinking about this question because some friends were discussing "what makes a good 80s action movie?" And they wouldn't accept my answer of "Con Air" because it was released in the late 90s, even though by their metrics is checked all the "80s action movie" criteria. To a college freshmen, would it seem any different stylistically, tonally, or textually from "Die Hard" or "Rambo?"
(I will say that part of that discussion focused on the ways other genres bled into the idea of "action," with both "Predator" and "RoboCop" being standouts. Personally I classify the original "Terminator" as a horror movie rather than an action movie, but you see how we got in the weeds of this particular discussion).