My wife and I are rewatching Once Upon A Time, and I just caught a fun little easter egg I don't remember from before: At one point (in S01E13), Regina gives Henry a handheld video game. Later in the episode, Emma sits next to him and identifies it as Space Paranoids.
Space Paranoids, of course, is the game that Kevin Flynn wrote and that Dillinger and ENCOM stole from him; the backstory MacGuffin that kicks off the plot of the original TRON.