The Paper Chase
THE PAPER CHASE (PG)
A struggling Harvard law student falls in love with the divorced daughter of his crotchety, peevish professor.
This is a good example of one great performance making the movie, with John Houseman stealing it away from every other cast member and making a rather mundane story incredibly watchable. Aside from this performance, the film isn't particularly special and certainly wouldn't be as memorable. It's a template which has worked in films since, to much better effect (Whiplash, an excellent example).
A television series followed, running for four seasons.