The One With All The Haste - S4-E19
Visible crew/equipment: After Joey convinces Chandler to agree to the bet, when Phoebe walks over to the recliners and tells everyone that she has a game, the camera can be seen moving at the right side of the screen. (DVD).
The One With The Fake Party - S4-E16
Visible crew/equipment: While Rachel is talking to Chandler she tries to get Joshua's attention so she pretends to laugh, and in the shot facing Joshua the end of the set wall can be seen, with the brick set wall from Central Perk on the other side.
The One With All The Rugby - S4-E15
Continuity mistake: During the rugby game, when Ross tells Phoebe and Joey that he thinks he's dying there are two hairsticks in Phoebe's bun in the shots facing her, but there's only one hairstick in her bun in the shots facing Ross.
The One With Joey's Dirty Day - S4-E14
Visible crew/equipment: After the exterior shot of Bloomingdale's, when it cuts to Rachel helping Joshua with his clothes the camera can be seen at the left side of the screen.
The One With The Dirty Girl - S4-E6
Visible crew/equipment: When Monica's explaining why she turned down the catering job, the large studio lighting is reflected on the TV when she tells Phoebe how much money she needs. Then just as Joey and Kathy walk in, the camera can be seen at the left side of the screen.
The One With Phoebe's Cookies - S7-E3
Visible crew/equipment: When Chandler and Jack, both wearing robes, are walking toward the whirlpool room, just as Chandler tells Jack that he'd feel more comfortable if Jack didn't tell anyone what had happened, we can see the shadow of the boom mic moving across the wall at the right side of the screen.
The One with the Monkey - S1-E10
Visible crew/equipment: While Phoebe's talking about David she mentions the movie 'An Officer and a Gentleman, ' and when she tells them that David is kind of like the guy she went with to see that movie, in the following wideshot the boom mic can be seen moving around at the top of the screen. (00:06:10)
The One with the Monkey - S1-E10
Visible crew/equipment: When Joey walks into Monica's apartment dressed as an elf, just as he takes off his coat we can see stage lighting at the top left side of the screen, above the large dangling star.
The One In Vegas, Part 1 - S5-E23
Visible crew/equipment: When Phoebe, Monica, and Chandler walk into Caesars Palace Casino, Phoebe notices Joey, and in the next wideshot we can see the camera panning around (it's on a camera crane, presumably filming the overhead angle seen in this scene), at the top right corner of the screen. (Widescreen version).
The One With All The Resolutions - S5-E11
Visible crew/equipment: After Monica and Chandler leave the apartment to go "do laundry," Rachel and Joey tell each other that they can't share what they each know, and just as Rachel sits down beside Joey, we can see the movement of camera equipment in the window's reflection, above the sink.
The One In Barbados, part 2 - S9-E24
Visible crew/equipment: During Monica and Mike's game, after Mike makes the comment that Monica should look in the mirror before calling herself a girl, in the following wideshot after the closeups the camera/equipment can be seen at the right side of the screen.
The One With the Male Nanny - S9-E6
Visible crew/equipment: After Rachel and Ross hire the new nanny, when it cuts to Chandler walking into Joey's apartment, we can see the opening in the wall beside the door.
The One With The Tea Leaves - S8-E17
Visible crew/equipment: After Monica and Chandler leave the apartment so Joey and Rachel can be alone, Rachel tells Joey that it's nothing and he tells her he's going to take-off, then in the next wideshot the camera can be seen at the left side of the screen. (00:08:30)
The One Where Rachel Finds Out - S1-E24
Visible crew/equipment: After Monica asks Rachel if there's someone else and shouts, "Why the hell are you dumping my brother?," when it cuts to Chandler sitting at the counter, the edge of the set can be seen at the left side of the screen, and also note the front door is wide open for the camera access. Additionally, when Joey joins Chandler at the counter the juice box has black tape covering its brand name.
The One With The Cake - S10-E4
Visible crew/equipment: After Joey describes Emma's funny Elmo cup to Phoebe, it cuts to Monica and Chandler walking in, and to the right of the door we can see the bulletin board is cut in size partially covering the hole in the wall. Later, when Phoebe and Joey leave after the wind-up toy race not only is this visible again, but through the hole we can see the other hole in Monica and Chandler's wall.
The One Where the Monkey Gets Away - S1-E19
Visible crew/equipment: When everyone walks in while Ross and Rachel are talking, just as Joey says that he doesn't need violence to enjoy a movie, in the small mirror behind Joey we can see the reflection of equipment moving, presumably a reflector screen.
The One with the Sonogram at the End - S1-E2
Visible crew/equipment: When Ross announces that Carol's pregnant, after Chandler says, "Kind of puts that whole pillow thing in perspective..." in the next shot of Ross and Monica we can see a crew member's sleeve at the left side of the screen. (00:07:30)
The One With The Dirty Girl - S4-E6
Continuity mistake: When Ross is making out with Cheryl in her apartment, he gets chocolate syrup on his fingers. In the following shots the chocolate syrup has disappeared. While he wipes his hand on the sofa, no way that would leave his hand perfectly clean.
The One With Ross's Tan - S10-E3
Visible crew/equipment: After Monica gets the call from Chandler about the fake car accident and leaves Phoebe with Amanda, in the next shot of Joey walking into his apartment the bulletin board that usually hangs beside the door is cut to about a quarter of its size, and it's covering part of the hole in the wall.
The One With Joey's Dirty Day - S4-E14
Visible crew/equipment: When Ross and Joey are explaining phase two of Chandler's break up (going to strip clubs), the camera switches from the girls to Ross and Joey. Behind them is Chandler and Joey's kitchen window where you can briefly see a reflection of someone passing by (crew member). At first I thought it could have been Chandler, since he was not in the scene, but after a few moments you see that Chandler has been in the bathroom the whole time. (01:35:00 - 01:39:00)
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.