From AMKandTheGang:
Maze Runner: You little shank/slinthead!
The rest from me:
The Mortal Instruments pt. 2: You asshat!
Harry Potter pt 2.: You Hufflepuff! (no offence, but srsly though...)
Percy Jackson pt 2.: You Octavian!
The Selection: The only thing you're good for is being an 8!
Divergent: You factionless!
Hunger Games: You're so stupid, probably from the Capitol as well!
*Doctor Who: You little Dalek!
*Sherlock: Don't talk, you'll lower the IQ of the entire street.
*Star Wars: You look like Jabba the Hutt!
*= fandoms, but known more for their movies/TV shows than their books.