Starring: Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matthew Perry, David Schwimmer, Matt LeBlanc
The One Where Ross Got High - S6-E9
Plot hole: Monica is trusting Rachel to make a traditional English trifle and being a top chef (or an even averagely intelligent human being) she would know what ingredients are used in one. So there's no way she could have missed Rachel cooking beef with peas and onions during the cooking process. Rachel's cooking it right there in Monica's kitchen while everyone else is there!
The One With The Birth Mother - S10-E9
Visible crew/equipment: When Joey's telling Phoebe about having been at a nice restaurant with his date and how she took fries off his plate, in the shots facing Joey in the restaurant we can see the end of the set wall, with a 2x4 framed plywood board and a heavy duty extension cord hanging there.
Trivia: Matthew Perry's wit is so legendary that the scriptwriters have often incorporated his gags into the show.
The One With The Dirty Girl - S4-E6
Question: When Joey asks why he can't give Kathy the pen, Chandler says, "Because she's not eleven. And it's not the seventh night of Chanukah." What is Chandler talking about when he says, "It's not the seventh night of Chanukah?"
Answer: Chanukah is a Jewish celebration that occurs around the same time as the Christian Christmas. The celebration lasts for eight days and it is customary to give a small gift on each of the eight days. There is no special gift required and the line about it being "the seventh night" of Chanukah is just Chandler's sarcasm.
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.