Christopher Reeve's face was the spitting image of the cartoon version--even the bone structure of his nose, jaw and chin. The first time the character rescued Lois from the stricken helicopter and he's about to fly off and she asks him, "Who are you?" there's a single shot of Supes when he replies, "a friend" that is the spitting image vision of the character in every comic I ever read growing up. He might have been presented differently in other versions but in the ones I read, that was the face I remembered. Reeve was a human incarnation of the comic vision of the character's physical looks. It's not surprising directors tried to emulate it with new actors.