It seems that most people do feel this is the definitive Jekyll/Hyde movie. There are so many versions....but the make-up, the acting and the quality of production in this 1931 hit from the MGM scream factory really does the trick!
The mild-mannered and easy going Dr. Jekyll theorizes that we all have a true "evil" self within. Through chemicals he finds he can prove that theory by bringing true evil out -- in himself. He succeeds all too well. His diabolical alter ego, Mr. Hyde begins to take control, suppressing Jekyll and tormenting a beautiful young woman. A great movie.
Special features in this edition: commentary by film historian Greg Mank, Bugs Bunny cartoon short HYDE AND HARE, theatrical trailer for the 1941 version.