Carmen is easily the worst character.
She's selfish, vindictive, one-track minded (sex), obsessive, and thinks the world should revolve around her. Examples: (I forget the names of her boyfriends, except Jason.)
*When Jason is getting into that baseball team, she thinks he should sacrifice his potential in order to stay with her, not worrying about his best interest.
*When Max is faking his birthday, she blackmails him. (Though he deserves it.)
*How many episodes DON'T revolve around her having boy trouble/George getting worried about her having sex?
*Jason. 'Nuff said.
*"DOES ANYBODY THINK ABOUT WHAT I WANT!?"
She's just overall unlikable, especially when compared to George and Ernie.