The One With Rachel's Date - S8-E5
Visible crew/equipment: When Ross shows up at Chandler's office and they both head out to go to the Hard Rock Cafe, just as Chandler walks out the door we can see the edge of the right wall set, allowing us to see the hallway Chandler just walked into and even Chandler's arm.
The One With The Video Tape - S8-E4
Visible crew/equipment: While Ross is talking into Joey's video camera, just as Rachel startles him and walks into the apartment we can see the holes in the walls of both apartments, 19 and 20.
The One With The Video Tape - S8-E4
Visible crew/equipment: After Rachel puts the videotape in the VCR, when she uses the remote to hit play it cuts to a closeup of the TV, and before the tape starts playing we can see the reflection of the camera dolly and a crew member wearing a white shirt, kneeling on the floor.
The One With Rachel's Date - S8-E5
Visible crew/equipment: While Phoebe and Tim are at Central Perk, when Tim's beeper goes off he blows Phoebe a kiss when he leaves, and as Phoebe catches that kiss and throws it away have a look at the left side of the screen, where the Central Perk wall ends we can see part of Monica's restaurant kitchen set - the door and the wall beside it. (Widescreen version).
The One Where Joey Dates Rachel - S8-E12
Visible crew/equipment: When Ross is wearing roller-blades while teaching his class, just as he points to the map and says, "Here," the second time, there's a hidden crew member that can be seen behind the end of the set wall with the map, at the left side of the screen.
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 With The Stain - S8-E7
Visible crew/equipment: When Brenda is cleaning the top of the cabinets, stage lights can be seen on the top right-hand corner of the screen. (00:11:45)
The One With The Baby Shower - S8-E20
Visible crew/equipment: Monica chases after Rachel's Mom to apologise and she falls over and you can clearly see the safety mat move when Monica falls on to it - it's blue and just down the first step. (00:22:00)
The One With The Cooking Class - S8-E21
Visible crew/equipment: When Joey and Monica are leaving the cooking class, the teacher asks about the difference between hollandaise and béarnaise sauce, and in the next shot of Monica and Joey we can see the shadow of the moving boom mic at the top left side of the screen.
The One In Massapequa - S8-E18
Visible crew/equipment: After the anniversary party, when Rachel and Ross are back at the apartment and Ross tells her that it was the easiest four hundred bucks he ever made, Rachel gets up and just as she walks around the couch we can see the reflection of the cameraman/crew member in the mirror on the wall, at the right side of the screen.
The One Where Rachel Tells... - S8-E3
Visible crew/equipment: When Phoebe asks Treeger not to mention the incident with the door to Monica and Chandler, just as Treeger uses the measuring tape we can see the opening in the wall beside the door.
The One Where Joey Dates Rachel - S8-E12
Visible crew/equipment: As Ross enters the classroom for his second lesson, he bursts in and for roughly five seconds, a boom mic is visible hovering overhead near the door. (00:10:15)
The One With The Cooking Class - S8-E21
Visible crew/equipment: In The One With The Cooking Class, just after Ross gets back from his date, a boom mike is hovering over Rachel's head. (00:17:25)
The One With Rachel's Date - S8-E5
Visible crew/equipment: When Chandler tells Bob "it's his fault", there is a bin behind him that reflects the stage lights. (00:16:10)
The One Where Joey Dates Rachel - S8-E12
Visible crew/equipment: In the scene of the classroom, before Ross faints, he says, "Why don't you all" and above his head near the clock, there is a boom mic. (00:18:50)
The One With Rachel's Date - S8-E5
Visible crew/equipment: As Phoebe walks into the restaurant kitchen, a crewmember's hand is visible stopping the door from swinging too much. (00:16:50)
The One With Rachel's Date - S8-E5
Visible crew/equipment: When we see Central Perk for the first time, you can see a stage light is reflected in the window. (00:05:20)
The One With Monica's Boots - S8-E10
Visible crew/equipment: When Chandler is giving Monica a piggy-back, Monica sees her boots in tan in the store window. In the non-widescreen version, the cameraman can be seen in the reflection of the glass. This was fixed in the widescreen version. (00:17:45)
The One With Monica's Boots - S8-E10
Visible crew/equipment: When Joey is talking to Bobby and Dina, lights and a boom mike can be seen at the top of the screen. (00:18:40)
The One With The Halloween Party - S8-E6
Visible crew/equipment: Right after Joey has finished his impersonation of Chandler, kids can be heard knocking on the door. When the camera pans to Rachel, stage lights can be seen in the top right-hand side of the screen. (00:05:15)
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.