1.Ross is wearing a little banana pin on the lapel of his jacket in the scene in Friends where he says goodbye to Marcel the monkey.
2.Abed had an entire story arc in the background of an episode of Community. He became friends with a pregnant woman, got in a fight with her boyfriend and delivered her baby in the back of a van all in the space of 20 minutes.
3.However, that's not all. In the first season of the show, we got a clue about how that same couple came to conceive the baby Abed delivered.
4.In an episode of Crazy Ex Girlfriend, Rebecca tells her boss that you shouldn't "knock someone else's fetish," even if it's being "choked by red licorice." A few episodes later we see Rebecca chewing on a Red Vine after sleeping with Trent.
5.The decorations in C.J's fishbowl on The West Wing were constantly changing references to the plot of the episode.
6.Similarly, the magna doodle board in Joey's apartment had a different sketch on it each episode which often corresponded with the plot.
7.And the board even showed up in the spin-off show, Joey.
8.There are a bunch of Lost references in the episode of How I Met Your Mother where Hurley makes friends with the gang. These include him talking about being stranded on a desert island and shouting out
those infamous numbers.
9.Once Upon a Time was created by two former Lost writers and there's a bunch of Lost-related Easter eggs in this show too. Most significant are a clock being frozen at 8:15, Regina living at number 108 and the characters consuming Apollo bars and MacCutcheon whiskey.
10.The guy who asks for Leslie's help with replacing a park swing in the series finale of Parks and Recreation was the same person who played the drunk guy she chased out of a slide in the pilot.
11.Remember the pants Walter lost in the desert in the first episode of Breaking Bad? Well, they show up in a scene where Walt's rolling his barrel of money through the area right before the finale.
12.In season five of The Office, Jim buys his parents’ house for Pam. While showing it to her, they come across a painting of a clown that Jim is unable to get off the wall.
Two seasons later, we learn that Jim and Pam did finally manage to get it down, because it ends up in the background as an item being sold at a garage sale.
13.On the last episode of season four of Buffy The Vampire Slayer, Tara says: "Be back before dawn." At the time, it doesn't seem like a big deal, but the comment actually foreshadows season five, when her sister Dawn is introduced.
14.And, in another episode, Buffy and Willow are seen buying textbooks. Buffy says: "I can't wait til mom gets the bill for these books. I hope it's a funny aneurysm." What was intended as a joke then actually comes to pass when Joyce dies from an aneurysm in season five.
15.For three seasons of Community, the word "Beetlejuice" was incorporated into three separate scripts. On the third instance of it being spoken, someone could be seen dressed as the character from the movie walking past in the background.
16.In the episode where Marshall's father dies in How I Met Your Mother, there's a countdown to his death throughout, with numbers in scenes decreasing from 50 to one when Lily gets out of the cab to reveal the news.
17.During the scene in 13 Reasons Why where Tyler is working at a library, Entertainment Weekly's Supernatural cover is visible behind him.
18.In the famous episode of Friends where the guys and girls compete in the trivia quiz which costs Rachel and Monica their apartment, one of the questions is about how many categories of towels Monica has. Joey and Chandler correctly guess 11.
But if you ever wondered what the actual categories were, they appear written on the boxes in a later scene where Rachel and Monica are packing in order to leave the apartment.
19.There's a reference to Tangled in a scene from This is Us, because Mandy Moore who plays Rebecca in the show also voices Rapunzel in the movie.
20.There's an equally clever crossover between Supernatural and The Walking Dead.
21.In The Simpsons episode where Mr Burns challenges the town to confess who shot him, everyone breaks eye contact with him except Maggie who ends up being exposed as the attempted murderer.