The Richard Donnor Cut is definitely the superior version of Superman 2. A lot of the silly moments from the theatrical version have been left out and scenes that were vital to the story have been put back in. The Best thing about this movie is the fact that they put Marlon Brando back in as Jor-El and it was wonderful to see new footage of him. Also if you own the theatrical version of Superman 2, you can still get this cut because so many scenes were reshot that it's almost a completely different movie, the only thing that's the same is the story. The only problems with the movie is the fact that it's unfinished and they had to put scenes from the theatrical version in the place of scenes that were never filmed. unfortunately since these 2 movies are different, putting in scenes from the theatrical cut made some pretty big plot holes. nevertheless the Donner cut is way better than the theatrical version.
Review of Superman II: The Richard Donner Cut
