Well I mean I'm not really at a position to say much on the subject since I went the very safe route with Nightwing and Ben 10. The later being an easy pick as a non comic book based superhero. But that doesn't mean there aren't characters who just wouldn't work for this. Hell last time this rp was done I made Peter Pan. You just have to get creative and think outside the box a bit. I also almost had Cyborg 009, considered Generator Rex for a bit, he'll someone was considering Ken Masters from Street Fighters (though I don't know if I could accept that for this at the moment). I was just thinking not too long ago someone from Animorphs could even work like Jake, Cassie, or Marcos.

Big Hero 6 had plenty of young heroes who'd work too...