Man, I'd take Aquaman over most any other hero in comics.  When done right he has a mostly unique setting, strong supporting cast (Meera and Orm especially) and an interesting position as a son of two worlds that struggles to get either to respect him.  

And Martian Manhunter is unnecessary, especially in a world that says Superman is overpowered.  I mean MM is just Superman with MORE bloody powers, and yet to my knowledge he's never done anything of significance or great import in his sixty odd years of being in publication.