Animator Robb Pratt is a huge fans of the old Superman serials from the late 1940s. So, he decided to create two animated shorts done to the music of those old serials, and the results are pretty impressive. Superman Classic and Bizarro Classic both present the opening chapters of much larger stories, but I almost prefer them that way, as you can fill in the rest with your imagination. Both shorts are followed by some great commentary, during which Robb reveals that the voice for Superman in the animated shorts is none other than John Newton, who played Superboy in the late 1980s TV show.
The Superman Super Site also did a recent interview with Robb that you can read here.