Quinoa wins easily. There's something about the self awareness of how ridiculous they is that comes through really well in Zidane's reactions to and treatment of them.
Also has legitimately good unforced moments of insight that make sense for their character.
Sign me up for annoying gimmick voices, shitty selfish personalities, and screaming gremlin children and animals. As long as the game knows these characters are uncool and annoying, I'll probably love them. I love pretty much all the characters in this thread except Claptrap. Claptrap's writing, much like Borderlands' writing in general, is too on the nose and doesn't know when to reign it in or let a joke breathe. Nothing kills an atmosphere like an unfunny comedy.