Look, Up in the sky. It's...

As you may have heard, Henry Cavill has been cast as Superman in the upcoming Superman: The Man Of Steel.  Now, ignoring the fact that this guy's only 6 foot 1, which is far too short for Superman, is making this movie really worth it.  Warner Bros. are only doing it because after 2012, they'll have to actually start paying the creators of Superman.  In other words, they're only making it to get a little extra from the rights.  The last time someone did this was in 1994, when Roger Corman made a Fantastic Four movie, without intending to be released.  Thanks to the glorious box of magic known as the Internet, it has since been bootlegged for all to enjoy.
What I'm really getting at here is, DC Comics have two Supes knock-offs.  The more similar of the two is Captain Marvel, or Shazam.  He was so similar to Superman, DC sued Fawcett Comics and DC owns the character.  Except, about all they do with him is get him to fight Superman in hero wars.  His story is that 12 year-old Billy Batson is handpicked by the wizard Shazam as a champion of justice, so that when Billy calls the wizards name, he turns into Captain Marvel.  And to think Josh Baskin wanted to be Big.  Captain Marvel once got the screen treatment in the 40's as a serial, this was even the first superhero.  Going back to the point, this serial was made because the writers couldn't do a Superman serial.
As for the other guy, that would be Martian Manhunter a.k.a. J'onn J'onnz a.k.a. John Jones.  His story comes about when he was at home in Mars, doing Mars stuff, when this old scientist teleports him Earth and inconveniently dies before he can reverse the process, damn old people.  Deciding that if he's stuck on another planet, he might as well live on it, shape-shifts into a human form, and becomes a plainclothes detective.  At first he solved people crimes, keeping his abilities, until there got to be a few alien invasion type things.  J'onn stopped being John and went out of hiding and became a hero.
Now Superman got his sense of right and wrong from an actual upbringing so that he didn't muck about with his godlike powers.  Billy's a freaking 12 year-old and J'onn got his knowledge of human culture from TV.  So, if you want a darker take, these two would be better than the Big Blue Boy Scout.