I'll put my vote in for SKY HIIIIIGH! 'Cause he's cheesy in a really fun way.
I quite like this show as well. The very concept of it is fun.
That being said, the whole [spoiler]Barnaby got his memories back 'cause Kotetsu called him "Li'l Bunny" was extremely cheesy; of course, better for Barnaby to have gotten his memories back than to continue on like that, but yeah.[/spoiler]
And, like others have mentioned, the other heroes don't get much screen time, which is too bad. I realize Kotetsu and Barnaby are the main characters, but considering how frequently we see the other heroes doing various things in most of the episodes, we don't really ever get to focus on them all that much outside of maybe one episode per character. This fact makes me sad.