5. Channing Tatum
Channing Tatum has always had the looks and the physique to pass for Superman, and in recent years, he's showed signs of developing the acting chops for this challenging dual role too.
Many of his early films lacked substance, but he's since branched out and worked with quality directors including the Coen Brothers and Quentin Tarantino.
Tatum has become a bankable star and he's due to head up a comic book blockbuster next year in the shape of X-Men spinoff Gambit. That could end up being a stepping stone to bigger and better things within the genre, if that's the path he fancies.
There's no reason why he shouldn't set his sights on Superman if Henry Cavill vacates the role. He did, after all, provide the voice of the superhero in 2014's Lego Movie.