James Caan was very nearly Superman once, and that movie would have been quite different.
Before Christopher Reeve indelibly left his mark on the role of Superman, there was a very different actor who was offered the role -- James Caan. And, as you might imagine, the script at the time (originally penned by Godfather writer, Mario Puzo) was also very different. In an interview with Howard Stern, Caan opened up a bit about it and revealed some details of what his Superman movie would have been like by describing one scene in particular.
When Clark Kent is just devestated cause she (Lois Lane) is so in love with Superman. Physically the office is setup in the paper (Daily Planet)... In order to get to Clark Kent's office you must pass through Lois Lane's office. So, there is no other way in. So, one day Clark is so pissed off (laughs) that she is in love with Superman, he says, aw screw it. And he rips his clothes off and he's got his Superman thing (costume) on under there. And he says, "Lois, come in here!" She comes in and looks at him, "That's sweet Clark, but you're no Superman." And she walks out. He looks and the mirror and says, "Maybe a little tuck here." It was all tongue-in-cheek.
But Stern also brought up some other roles that Caan had also been rumored to have been offered. One in particular, Han Solo, Caan denied, but then said, "They didn't want an actor, that's why they got Harrison Ford."
Wow! When asked why he didn't like Ford, Caan said, flippantly, "He called me the wrong name or something." As slights go, that's not all that bad. But don't tell Caan we said that! he may not have been the right choice for Superman, but he'd make one terrifying Lex Luthor.
(via Comic Book Movie)