John has an incurable weakness for New York-style pizza, steak (rare, as in hit the cow over the head), and brocolli. He doesn't like admitting the brocolli, because he hated it when he was a kid and he can still hear his dad lecturing him about eating green vegetables.

Also, John will never ever admit he likes the soft, irritated huff Rodney makes whenever he's confronted with people who are too stupid to be endured.