A Superman story? That's easy.

All of Superman's rip offs would be teleported into the sun, and Superman proceeds to beat all of them at once.

A more serious story would be about Superman attempting to stop World War 3, all the while slowly losing his powers due to pollulation and smog severely reducing the amount of sunlight that enters the atmosphere.

The story ends with all tyranny wiped off the face of the earth, and the Justice League appointing trustworthy individuals to control the government while the JLA becomes a world peace keeping force. It would have to be Else world, of course, but who cares?

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All this Superman/Batman hate is just..blergh. They're completely different personas; total opposites. Fans of one are more likely to dislike the other. Just because you dislike a character means they're a poor character - it just means you dislike the character.  Personally, I think they're both great.