Though the horror-film genre has often had narrow, if enthusiastic, audiences, through the years, a number of horror films have broken through and become some of the biggest box office hits of their era. "The Phantom of the Opera" (1925) was a huge hit in the silent era, making the equivalent of more than $100 million in today's dollars. The film starred Lon Chaney, the "Man of a Thousand Faces," and Mary Philbin.
Universal Pictures built its success on horror films in the '30s and '40s. One of the biggest hits of 1931 was a now-classic version of "Frankenstein." The film stars Boris Karloff, left, as the monster.