*Season 3*
When Ross and Rachel are arguing because Rachel told Phoebe about Ross's fantasy, Ross is taking a chocolate bar out of the fridge, takes a bite, then the bar is complete again, then it has a bite out of it again ... (Thanks to Roni from Roni's Ross and Rachel Page)
1) When Phoebe says to Monica "and that's why we don't invite you to play", her hands are in one position, and at the next cut they change position (Thanks to Roni from Roni's Ross and Rachel Page) 2)During the Milk infomercial, Joey makes quite a spill. They cut to another scene (not showing the spill) for about 5 seconds. In that time there is no way he couldn've cleaned up the mess, but when they show the table again it's completely clean. (Ciro G.)
Phoebe gets hummus on her dress and it's quite a big spot.She says that she can't wear her dress anymore, it's ruined (or something like that) but when she comes out of the bathroom, the spott is a lot smaller, than before she went into the bathroom. Now it's just a little dot.... (Marthe Scheffer)
Joey moves the hamper in Monica's bathroom to the middle of the floor. In the next shot, the hamper is completely gone. (Shay)
1) The flashback is set one year before the pilot and the numbers on the doors reads 19 and 20. But in the pilot, the numbers read 4 and 5. Then later on in season 1, the numbers on the door have 19 and 20 on them. Therefore, the numbers in the flashback should have read 4 and 5. (Shay)
2) In TOW the thanksgiving flashbacks, Rachel and Chandler met twice, but in TOW the Flashback, they didn't know each other. (Shay)
In TOW The Girl From Poughkeepsie, Monica says that in kindergarten they needed somebody from junior high to do the seesaw with her because she was so fat, but in TOW Rachel Quits she says that she started putting on weight when she was a brown bird and that is way past kindergarten more like 3rd or 4th grade. - (Nitro)
1)In the guys apartment, Ross is holding up two suits. The blue one in his left hand and the brown one in his right hand. Just before the scene finishes you see that the blue one is now in his right hand. (Shay)
2)When Ross leaves Rachel to go get a cab, Rachel asks for him to stay with her. He replies that sure and that he only needs to make a call. Right after that, Ross opens the door to review not the inside of Monica and Rachels apartment but the set. (Marthe Scheffer)
In the last few episodes of season 3, Joey has very very short hair. In the first scene of "the one with the ultimate fighting champion, he has longer hair, but then it's short again for the rest of the episode. (My guess is, they filmed it at an earlier date because it was the only time they could get Robin Williams and Billy Crystal, who were also in that scene.)(Bill W. Found in FWS)
When they come in the beach house, the sand is wet, then dry.(Nitro)