Dr. Jekyll and Mr. Hyde (1932)

Granted, I haven't seen every adaptation of Robert Lewis Stevenson's classic horror story, but after watching Rouben Mamoulian's version, I am prepared to call this best. Frederic March plays the duel role of tormented good doctor, and his brutal counterpart. His Hyde is ape like in both appearance and even in action. He abuses and psychologically tortures a young barmaid in some of the more frightening and disturbing passages of the film. The film also has some strong and overt erotic undertones. Mamoulian was one of cinema's earliest innovators. The 1930's presented some of the most visually bland films in American history due to the advent of sound and the unwieldy size of the camera's. Mamoulian, however, refused to be bound by such limitations. His camera moves remarkably. There is some spectacular subjective camerwork involving Jekyll looking directly into a mirror and watching his own transformation into Hyde -- a remakable visual feat even today. A very unusual horror film, and one of the best of the era.