I like the ones on Simpsons and Futurama. If you're a fan and know the names and stuff it's easy to pick up on. I like it when they poke fun at the writers, hehe.
In Futurama they log onto the internet which is 3D and meet up in a chat room. Some of the writers of the show are in that room looking for women. Matt Groening was in that scene but he had himself removed, lol. David X Cohen was in the laser quest type scene, and Fry zaps him.
For the chatroom scene they wrote 'nerRAB in a room' for the script and the animation came back with the writers being the nerRAB, lol.