Source: thaiembassyuk.org

7. Ultraman

What if Superman were the greatest supervillain on earth? Well, you'd have Ultraman, the Superman of Earth-3.

On Earth-3, good and bad are inverted. President John Wilkes Booth was assassinated by the cowardly Abraham Lincoln, Alexander Luthor is the greatest hero of all time, and the Crime Society of America rule the nation with an iron fist.

Born El-Kal (Spanish for "The Kal") Ultraman came to Earth-3 and gained incredible powers. Given strength by Kryptonite and (sometimes) weakened by the sun (it depends on the version of the character), Ultraman helped form the Crime Syndicate with his girlfriend Superwoman and rival Owlman, among others.

Ultraman would make a great movie villain, showing what Clark could have become without the influence of Johnathan and Martha Kent. It'd also give him an equal match who WASN'T Zod, for a change. Plus, it'd be a great way to introduce the DC Multiverse into the movies. And I love me some Multiverse stories. I even like Hypertime.