The title should say which character should be in DC not Marvel. LOL

I would absolutely love it if Thor was a DC character. He could fight more powerful people like Lobo and DC characters seem to be more powerful than Marvel ones, so he would have several better strength feats.

Thor is a DC character. He was in the Sandman.

Punisher I think...

I would love to see the Fantastic Four in DC. Think they would bounce off their heroes and villains well. Or Spidey. Especially with SSM, it'd be interesting to see how/if Dr. Spiderpus would take down characters like the Joker or Lex Luthor.

I think the punisher would do good as a Batman character