Rachel invites her sister Amy thanksgiving. Phoebe teaches Joey how to lie. Chandler worries about whether he will be a good father.
In my opinion there are many highlights of this episode. Rachel and Amy's fight is a very funny part and Monica collapsing when the plate smashes is very funny. Phoebe ranting on about how she doesnt believe that men have walked on the moon is priceless. Monica telling the others not to scracth the plates, but eat their food in the air makes me laugh just to think about. Joey fogetting to be at the parade and forgetting to take his grandmother to the aiport is hilarious. Amy forgetting Emma's name, and thinking Phoebe is Emma is also very funny.
Anybody who watches this episode, and gets all the jokes will probably understand why so many people say this is the best episode.