Rao knows I love Richard Donner's Superman (1978), the film that cemented my love for the characters and stories that made up the world of Clark Kent and his heroic alter ego. Donner's adaptation captured almost the full gestalt of what makes the character great: his goodness, his vulnerability, the tragedy of his birth, the irony of being two-thirds of an impossible to reconcile love triangle, the weight of his self-imposed responsibilities. And Donner captured these elements in a film that avoided campiness (save perhaps when it comes to the villains) and treated the mythos with respect.
But another great Superman story emerged in 1978: Superman vs. Muhammad Ali, a gorgeous oversized tabloid comic book crafted by two legendary figures in comics: writer Denny O'Neil and artist Neal Adams. While the concept sounds like a gimmick of questionable taste, O'Neil and Adams put the two icons, one real, one imagined, on equal footing through good storytelling and clever use of the mythologies of both men.
The plot is really quite simple: an alien armada arrives in Earth orbit. It's the Scrubb, a renowned warrior species who've heard that Earth, too, is a planet renowned for its martial prowess. An emissary of the Scrubb demands that Muhammad Ali, who they dub Earth's greatest warrior, must fight the Scrubb champion in gladiatorial combat. Refuse, and Earth dies under a hail of nuclear missiles.
Of course, the alien emissary finds Ali just as he's being interviewed by Clark Kent, Lois Lane, and Jimmy Olsen, Clark slips away to change into Superman and argues he should be the one to fight the Scrubb champion, acknowledging that while Ali is the world's greatest human fighter, he, Superman, is superhuman...to which Ali responds if anyone's going to fight for Earth, it should be someone born on Earth.
The alien emissary doesn't care who fights as long as someone does, so he sets up a primary bout that will take place in an arena that nullifies Superman's powers, guaranteeing a fair fight. Well, "fair" in the sense that now you have a guy that's still pretty strong but who's never needed any training to win fights going up against, well, Muhammad Ali.
While this setup sounds like silly kid stuff, the storytelling abilities on hand really sell the idea, and the narrative gives both Ali and Superman plenty of moments to shine, with three great boxing sequences, some Mission:Impossible style covert ops, and a spectacular space battle. In the end it turns into a legitimately exciting space opera that, if filmed with care and an admittedly huge budget to capture Neal Adams' incredible visuals, could have rivalled the Star Wars films for escapist entertainment back in the day.
Naturally you'd use the cast from Donner's Superman, and Ali would, of course, play himself. Somewhere out there in the multiverse, you can see this movie...