I think 30 Rock‘s last big meta-joke, about the fact that a “year” on TV ends when the season does (“What are you talking about? It’s May!”), is my favourite joke about the end of the regular season. The most famous is probably this one, where an episode was literally stopped in mid-story by the arrival of the summer hiatus, but like a number of jokes from Moonlighting, it maybe goes a little overboard with the fourth-wall-breaking. Though what made it famous was the moment at the end when it turns out that while everybody else is an actor on the series, “David” and “Maddie” are apparently real people who will continue having unresolved sexual tension throughout their separate vacations. That’s the sort of meta-humour that can make your head explode if you think about it too much.