5. He-Man
He-Man and Superman have actually come to blows on two occasions in the comic books before and it's pretty hard to argue that seeing the two super-powered heroic warriors arguably two of the most admirable and iconic characters in comic book history going at it against each other in a movie would be nothing short of amazing. The duo first met in 1982s DC comic "Superman and the Masters of the Universe" when the man of steel flew through a dimensional portal and ended up on He-Man's home planet of Eternia. When Skeletor found out about Superman's presence on Eternia, he took an interest in him and the Kryptonian fell prey to one of the evil sorcerer's spells and was forced to fight He-Man whilst under Skeletor's mystic control. Of course, in the end, the two heroes team up with each other when the spell is broken and they promise to help each other out in the future if indeed such awesome help is needed. More recently, however, there was a "DC Vs Masters of the Universe" arc (in 2013, nonetheless) in which Skeletor escaped from his last battle with He-Man and headed to DC Earth to recover. Once he arrived there, he set a plan in motion to siphon off Earth's core magic. He-Man and the Masters of the Universe follow Skeletor to Earth but are confronted by the primary heroes of the DC Universe; the Justice League. There are undoubtedly some epic movie possibilities with that story and, now that DC have the rights to both franchises, they should be seriously thinking about bringing this titanic meeting to the big screen.