The One With The Truth About London - S7-E16
Continuity mistake: When Joey is reading his speech about all the giving and receiving, Chandler has his legs on the table at the coffee shop. You can see his shoes on the table when they show Joey, but when they change the shot to Chandler his legs are on the floor and crossed. (00:10:55)
The One With The Truth About London - S7-E16
Continuity mistake: In the flashback, Chandler says to Joey that he is watching a movie when the camera cuts to show the blank screen. In the reflection, you can see that there is no-one present in the room. (00:18:20)
The One With Ross's Inappropriate Song - S9-E7
Continuity mistake: When the veal is served, Phoebe looks at her plate twice. (00:16:55)
The One With The Chicken Pox - S2-E23
Continuity mistake: When Monica says about Richard not having a 'thing', her arms change place depending on the shot. (00:14:10)
The One with the Stoned Guy - S1-E15
Continuity mistake: When Chandler shows Phoebe his office he opens the blinds. In the next shot a pile of books have appeared on the window ledge. (00:14:40)
The One with the Stoned Guy - S1-E15
Continuity mistake: During the scene when Chandler arrives with his test results, Phoebe is reading a book with a red section on the left hand page. In the next shot, the red on the page has vanished. Then, in the next shot, the red page is back again. Also Phoebe's left hand moves between shots. (00:07:15)
The One Where Chandler Crosses The Line - S4-E7
Continuity mistake: When Ross and Phoebe are talking in Central Perk, Phoebe's position changes. (00:14:45)
The One With Princess Consuela - S10-E14
Visible crew/equipment: At the very beginning of the episode when the friends are at the table a microphone dips into the shot above the table. (00:00:05)
The One In Massapequa - S8-E18
Character mistake: In the early years, the gang are talking about their pets dying and their parents saying they sent them to a farm and Ross thinks that actually exists. He said that they sent their dog Chee Chee there and HE could run about chasing animals. Then in TOI Massapequa, Monica is preparing her speech and she tells Chandler about Chee Chee and said SHE died when Monica was in school, and when Parker asks whose dog it is, Monica says HE's my old dog. Then during her speech, Monica says HER and Nana are gone. (00:15:30)
The One Where No One's Ready - S3-E2
Other mistake: When Monica beeps into Richard's machine and changes the outgoing message, she always presses the same two buttons when trying to interact with his machine, but gets a different result each time. (00:19:00)
The One with Two Parts: Part 1 - S1-E16
Visible crew/equipment: When Rachel is taking the Christmas lights down, a boom mic is visible as the camera pans down when we first see her. (00:21:15)
The One With The Embryos - S4-E12
Audio problem: When Rachel is banging on the door at the start, the sound does not match the actions. (00:01:00)
The One With the Breast Milk - S2-E2
Continuity mistake: When Ross thanks Monica for going shopping with his new girlfriend, Monica has her arm up, and the camera cuts, the arm is down with no time to do so. (00:04:00)
The One With Ross's Thing - S3-E23
Other mistake: When Ross goes to see Guru Saj, he has his 'thing' removed. However, it is really obvious that Guru is not going anywhere near the thing, because you can see that Ross' shirt is still tucked into his trousers, and the Guru just rubs his hands along the shirt. (00:16:35)
The One With The Embryos - S4-E12
Other mistake: Ross makes up the questions for the quiz. There are two groups of questions, one for the girls and one for the boys. Each one has four categories; there are four questions in each category. From these 16 questions, Ross asks ten. Thus, there have to be six left after the quiz. But in one group, seven questions can be seen (there are seven cards left). (00:12:50)
The One Where Ross Dates a Student - S6-E18
Visible crew/equipment: Just after Ross' girlfriend leaves the Central Perk, Ross walks towards the couch. Just before Rachel starts talking, the stage lights can be seen reflected in the glass above the entrance. (00:17:00)
The One With The Ultimate Fighting Champion - S3-E24
Continuity mistake: When Robin Williams calls Billy Crystal a b*stard, Monica's purse goes from on her lap to being on her shoulder. (00:01:30)
The One Where Ross And Rachel Take A Break - S3-E15
Continuity mistake: When Rachel is sitting in the window seat talking to Mark on the phone, the glass and the wine bottle move closer to each other. (00:15:50)
The One With All The Jealousy - S3-E12
Continuity mistake: When Ross and Rachel are talking about his playdate with the stripper, a lady in a black vest talks to the people at the table behind them, then goes to the bar and shakes hands with a lady in a black jacket. She does all this again in another shot. (00:19:30)
The One With Phoebe's Dad - S2-E9
Continuity mistake: In the scene when Joey is asking Ross to show him the presents he bought, Joey uncrosses his legs twice. (00:03:20)
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.