Firefly shout-out in recent episode of Powerless on NBC.

http://www.nbc.com/powerless/video/van-v-emily-dawn-of-justice/3482417 The writers give Alan Tudyk an opportunity to say hello to some old friends midway through S1 Ep7, “Van v Emily: Dawn of Justice” (link is to episode playback at NBC.com). It comes near the top of Act 3, roughly at the 14:30 mark.