Favorite meta moment?

I love when Pierce talks about the bully that Jeff fights, saying, 'I know Mike's type, used to be a nerd and is now some meathead' (definitely not the exact quote) Referencing how Anthony Micheal Hall(Mike) played Brian, the nerd, in Breakfast Club.

Anyways, what are your favorite meta jokes? Hopefully there's some I haven't yet heard of/noticed!