Revealing: In the one after Monica and Chandler get married, Chandler says he can't dance because his shoes are slippery. If you look closely, he managed to slip so much by standing on the bottom of Monica's dress, not because of the shoes.

Continuity: When Monica tells Joey and Ross she is not pregnant, her hand goes to her chest, then down to her side, and then back to her chest.

Continuity: 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.

Continuity: When Rachel spits out the champagne for the first time, her necklace is center chest. When the camera cuts it is far right.

Continuity: Just as Ross and Mona are about to dance, her arms are crossed. The camera cuts and they are on her hips.

Continuity: The way Phoebe holds her flowers when told to smile changes depending on the angle.

Continuity: When Monica and Rachel are discussing Phoebe, Rachel's hands go from playing with the table to dry washing depending on the shot.

Continuity: Near the end when Monica and Chandler are going on to dance for the last time, Monica speaks and her hair is neatly behind her right ear. The shot then looks to Chandler before going back to Monica immediately. However her hair is suddenly behind her left ear when she can't have moved it as her hands are in the shot at all times.

Continuity: When Joey and Chandler are discussing Joey's shoes, the length of the sleeve round Joey's neck changes depending on the shot.

Other: When Chandler says "We just got married. Right there!" and points. We hear a small 'ding' and Monica asks "Is that your ring?" But when Chandler pointed, you can see that all of his fingers except his index finger are closed to his hand. So the ring couldn't have come off.

Continuity: When Monica says she wants to dance, her hair is always changing depending on the shot.

Plot hole: Chandler and Ross are surprised to notice that Joey has very small feet. It's well beyond suspension of disbelief to think that at the least Chandler (who, apart from being his best friend, has been his roommate for 8 years) has never noticed the size of Joey's feet before.