I'm stuck. I think "Superman" is a likeable, although dated, superhero movie (although the F/X is good, it still looked like Reeve was superimposed against a green screen background). Considering the time period it was made in and how Superman emerged in the comics, it was faithful and entertaining. But it's pretty campy in places - Luthor just being able to immobilize Superman with a big Kryptonite necklace, Ned Beatty's broad comic performance, etc.. didn't seem in tune with the comics. It's definitely blessed by the performances of Christopher Reeve and Margot Kidder, though.
"Batman Begins" is buoyed by a good performance by Christian Bale. He's able to make a good Batman and a good Bruce Wayne, and the film took itself seriously, yet there was humor in the right spots to break up tension. And the characters were cast perfectly and more importantly, the movie can stand up to repeat viewings.
I will say, like the person before me, that "Superman: The Movie" is a classic and set the standard for comic-book movies, but I find myself reaching for BB and watching it more than I do "Superman". There's something about BB that appeals to me more than "Superman".