Complete Monster: Protoboy. He would murder his own brother, destroys everything just for the sake of destroying it, and is just generally an unpleasant character. It could even be argued he's more evil than Kamikazi.
Crowning Moment of Funny: "Hey, Mr. Sensitivity, let's see you get in touch with your inner vacuum cleaner, okay?"
Ear Worm: "OH! I know a song that gets on everybody's nerves, I know a song that gets on everybody's nerves..."
Fridge Brilliance: The "Robotboy = Pinocchio" equation seems simple at first: Robotboy wants to be a human, just like Pinocchio. But remember how Pinocchio is/was a puppet? In a sense, Robotboy is a puppet, too — he does whatever Moshimo/Tommy/Gus tells him to do because they're his friends, but Kamikazi can also control him in a different way.
Fridge Horror: Both Robotboy and Robotgirl are walking weapons platforms with the minds of children.
Fridge Logic: After Protoboy was permanently deactivated, it's shown that Kamikazi put him in a reject closet. In that state, Protoboy was harmless — why didn't Kamikazi just take him and reprogram him again to be less evil?
If Gus' parents are Amish, why are they living in the city?
In a sense, Constantine. Sure, he is a bad guy, but Kamikazi mistreats him very badly, and on some occasions he is shown to be nicer than his boss, such as "Teasebots". Also, in "Kamispazi!" it's implied that he grew up at an orphanage. If that doesn't make you want to hug him, nothing will.
Tommy too, especially in "I Want That Toy" and "Crying Time".