I know it's one of the big ones that everyone is familiar with... but Nosferatu is so creepy that it still works. I love that movie.
That being said, I am a huge Lon Chaney fan. (Sr. - Though he was not really a Sr. - Creighton Chaney changed his name to Lon Chaney Jr. to break into the movie biz). Phantom of the Opera is just one of my all time favorites.