The One with the Stoned Guy - S1-E15
Continuity mistake: When Chandler says he can't work out what he wants to do working at his job, he is standing behind the sofa. In the next shot, he is in front of the sofa sitting down. (00:02:50)
The One with the Stoned Guy - S1-E15
Continuity mistake: Just before Chandler tells everyone he quit, he holds out both hands in front of him. In the next shot, his left hand is by his side. (00:02:05)
The One with the Stoned Guy - S1-E15
Continuity mistake: In the scene where Monica is explaining to Rachel that she has hired her friend Wendy as her waitress, Rachel is holding a water bottle in one hand and the cap in the other. Monica moves towards her and Rachel is pointing her hand in Monica's direction and then in the next shot we see Rachel from another angle and her hand is holding the cap on top of the bottle too fast to have happened in normal time. (00:08:40)
The One Where the Monkey Gets Away - S1-E19
Continuity mistake: When Ross and Rachel argue about losing Marcel, the bottle of wine Ross re-corks is sitting on the table. Neither of them touch the bottle at any point after this yet when the woman from animal control arrives, the bottle has moved to the side table. (00:10:15 - 00:11:10)
The One with George Stephanopoulos - S1-E4
Continuity mistake: When Joey jumps over the sofa to give Ross the tickets, one of the pages of Ross's magazine is sticking out towards him. In the next shot it is gone. (00:02:40)
The One Where the Monkey Gets Away - S1-E19
Continuity mistake: When Phoebe gets hit with the tranquilizer she falls on the couch with no dart in her leg. When she stands up it appears out of nowhere. (00:15:50)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: At the end of the episode, as a customer in Central Perk asks Rachel for more coffee, Chandler has set his cup of coffee on the table. In the next shot, he is holding it again. (00:28:05)
The One Where Underdog Gets Away - S1-E9
Continuity mistake: When Rachel gets her mail off Monica she puts it down on the couch and picks up a sealed envelope. The camera cuts and the envelope is now open with no time to open it. (00:07:25)
The One with Two Parts: Part 2 - S1-E17
Continuity mistake: Just before Ross drops the cake, Rachel is pouring crisps into a bowl with her left hand holding the bottom of the bag. In the next shot, she is holding the bottom of the bag with her right hand. (00:05:50)
The One Where Nana Dies Twice - S1-E8
Continuity mistake: When Ross and Monica are visiting Nana, Ross has his hand on Monica's shoulder. In the next shot it is gone. (00:05:05)
The One with the Monkey - S1-E10
Continuity mistake: Just after Chandler explains the situation to Janice, she goes off crying, and Ross takes a photo. The flash is much brighter than it should be - the screen's whited out to disguise a jump cut - after the flash Chandler's noticeably further back than he was before. (00:17:45)
The One with George Stephanopoulos - S1-E4
Continuity mistake: When Rachel explains to her friends about her job, for the first half of the scene there is a cushion behind her back. When Rachel says, "This is what I'm doing now, I've got this job." The cushion disappears. (00:07:40)
The One Where the Monkey Gets Away - S1-E19
Continuity mistake: When Rachel tells Ross that she lost Marcel, the bottle of wine has the cork sticking half way out. In the next scene which continues directly on from before as Ross and Rachel argue, the cork is back in the bottle. (00:10:15)
The One with the Dozen Lasagnas - S1-E12
Continuity mistake: During the song at the beginning of the episode, keep your eye on Ross's mug. He is holding it in his lap, then there is a shot of Monica with Ross's empty saucer on the table. In the next shot, the mug has appeared on the saucer. (00:00:30)
The One with the East German Laundry Detergent - S1-E5
Continuity mistake: Right at the start in the coffee shop Chandler's legs are always switching position depending on the angle. (00:00:05)
The One Where Monica Gets a Roommate - S1-E1
Other mistake: Ross is a paleontologist but is seen working with the display on early humans which would be more of a job for an anthropologist.
The One with the Fake Monica - S1-E21
Continuity mistake: When Monica, the fake Monica and Rachel are in the girls' apartment talking about the two Monicas auditioning for CATS, Monica (real) has a baguette and a bowl of sandwich filler on the table. In one shot of all three of them, she opens the baguette and starts filling it, then the camera goes in for a close-up of the real Monica and she opens the same baguette and starts filling it again. (00:10:50)
The One with the Ick Factor - S1-E22
Continuity mistake: In the scene where Chandler and Phoebe come into the coffee house from Phoebe's first day as his secretary, Phoebe makes no discernible effort to order - but after Chandler says it pays to know the man who wears his shoes the shot cuts to her holding a large latte cup which was not visible earlier in the scene. (00:07:00)
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)
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.