The One With The Donor - S9-E22
Continuity mistake: When Monica is asking Zack if he or any of his blood relatives has diabetes, Zack's cutlery changes position twice. In the shot facing him he has his fork in his left hand and his knife in his right. When it changes to a side shot, he is gesturing and doesn't have anything in his hands, without having time to put the cutlery down. Then when it cuts back to a front shot, he picks up his fork, which is now on his right, and starts eating. (00:14:30)
The One With The Mugging - S9-E15
Continuity mistake: When Rachel is asking Joey what he's doing with all the liquid, her drink changes places depending on the shots. (00:14:50)
The One With The Engagement Picture - S7-E5
Continuity mistake: When 'Hums While He Pees' hands Phoebe the tickets for the ballroom dancing, they switch hands depending on the camera angle. She takes them in her right hand, but in the shot from behind she has them in her left hand. (00:08:25)
The One With The Dirty Girl - S4-E6
Continuity mistake: At the beginning of the episode where they are watching Ross through the window, Phoebe is leaning forward and standing to the left of the pole next to Chandler. When the shot changes to Ross coming through the door, she is suddenly standing up straight and is now behind Joey and Chandler. (00:00:10)
The One With the Baby on the Bus - S2-E6
Continuity mistake: In the scene where Chandler and Joey want to meet women with Ben, Chandler is holding the baby. A little after Chandler says, "Oh seriously you want him?" The position of Chandler's hands holding Ben changes between shots. (00:05:55)
The One Where Rachel Tells... - S8-E3
Continuity mistake: In the scene after Rachel has told Ross, she finishes the magazine and tells him there is no pressure on him, his hand is on his chin, then almost instantly his hand is down. (00:11:20)
The One With Ross's Wedding, part 1 - S4-E23
Continuity mistake: Rachel is cutting flowers and she and Phoebe are discussing if she loves Ross. Phoebe's necklace switches sides every time the shot goes back to her. (00:07:35)
The One Where Rachel Smokes - S5-E18
Continuity mistake: Joey's snowcone changes during the scene with Ross at the party. It goes from rounded to more flat to rounded, and from plain ice to being able to see the flavoring to ice again. (00:20:00)
The One With The Boob Job - S9-E16
Continuity mistake: When Mike goes to leave Phoebe's apartment at the start, he puts his jacket over his arm twice. (00:02:10)
The One Where Chandler Gets Caught - S10-E10
Continuity mistake: Ross claims he looks into Monica and Chandler's and watches them eating dinner and watching TV. His apartment is a floor lower down than theirs and with the balcony wall, the sofa and tables distance from the window and the fact the bottom of the window is higher than the floor, there is no way Ross would be able to see that far in. We have seen in the past that he can basically only see who is at the window. (00:19:05)
The One Where No One's Ready - S3-E2
Continuity mistake: When Joey refuses to give Chandler the chair, Phoebe gets hummus on her dress, but in some scenes the stain is much smaller than others. (00:07:00 - 00:08:00)
Continuity mistake: When Ross says , "Yes, I am." after Mona calls him sweet, His hands are by his side. Next shot one of them is by his chest. (00:16:30)
The One With Joey's New Girlfriend - S4-E5
Continuity mistake: In the bar, Kathy is trying to set Chandler up with one of her friends. When the camera is facing Chandler, we see Kathy's hand rubbing Joey's back, but when it cuts to a front shot of Joey and Kathy, her arm is down in front of her. Then without having had enough time to move, her elbow is up on the table and she is holding hands with Joey. (00:16:10)
The One Where Joey Dates Rachel - S8-E12
Continuity mistake: At the end Ross rips the map but in the next shot it's repaired. (00:21:00)
The One With Ross's Wedding, part 2 - S4-E24
Continuity mistake: In the scene where Monica and Ross discuss how Emily has decided to call off the wedding after Monica suggests they postpone the wedding, Monica is wearing a black watch on her left wrist. This disappears and re-appears a number of times throughout the scene. (00:15:00)
The One Where Rachel Tells... - S8-E3
Continuity mistake: In the scene where Monica and Chandler are trying to get in the first class lounge, Monica has a green bag on her left shoulder. It switches mid-scene to her right hand, and then appears back on her left shoulder. (00:08:40)
The One With The Blind Dates - S9-E14
Continuity mistake: At the end of the blind date, in shots of Rachel, her date Steve is holding her hand with both of his, but from the reverse angle he's only using one. (00:18:45)
The One With The Truth About London - S7-E16
Continuity mistake: When Rachel goes to Carol's house and tries to tell Ben to stop playing pranks, her bag changes from being on her shoulder to in her hand in almost every shot. (00:12:25)
The One With All The Haste - S4-E19
Continuity mistake: Phoebe comes in wearing Santa pants. When Joey and Chandler point this out, Chandler's legs are crossed or uncrossed, depending on the camera angle. (00:04:10)
The One With All The Wedding Dresses - S4-E20
Continuity mistake: Rachel takes a drink from the Jones Soda and sets the bottle down. A second later, the bottle is fuller than it was to begin with. (00:10:05)
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.