Connor- "Nice socks." Also sort of doubles as a Catch Phrase when mockingly dealing with authority.
In the second book, a safe house for former tithes decides to put on a dance. Everyone just stands around awkwardly and doesn't dance, so the frustrated adult DJing decides that it's going to be mandatory for everyone to do the Hokey Pokey. About ten seconds into the song, he realizes that it's probably a bad idea to sing about individual body parts to a bunch of ex-tithes, and tries to jump to the "put your whole self in" line right away. The teens, however, find this hilarious and it actually serves as the ice-breaker for the party.
Connor remembering his conversations with his tattoo while high in the third book.