1. Spider-Ham. Always loved that guy. The mask did a great job of hiding the fact that he's teen pig photographer Peter Porker. Underrated.
2. Count Chocula. Probably more suited to be an X-Man, but he would rival Hulk for the "loose cannon" role.
3. Betty. You know, like from Betty and Veronica. She may not seem like much on the surface, but is clearly an immortal with death stare powers. Read between the Archie comics lines.
4. Felix the Cat. That little scamp is always wriggling himself out of hairy situations. Good cat to have on your side.
5. Super Man. Because it would be so demeaning to him to have to be a part of a team that takes down threats too big for him to handle alone. Judging from how he always acts as though the Justice League of America is so lucky to have him around.