We know FRIENDS had a lot of good, memorable episodes but I think there were also a few very bad ones like...
918 - TOW with the Lottery. I hated this episode because all the characters seemed to have a personality change. I couldn't believe they would fight over lottery tickets and the things they said to each other was not funny but mean-spirited. I especially did not enjoy when Phoebe asked what's more important: Friends or Money? and Monica was the one that said Money. What bother me most about the episodes in the later seasons were that while some of the jokes are funny, they do not seem fitting with the characters - especially Monica and Phoebe. Monica became pretty mean and Phoebe just changes her principles in a lot of occassions
712 - TOW They're Up All Night I could not believe that how boring ALL the storylines in this episode were. I thought it would be good since I enjoyed episodes that has a central plot (TOW No one is ready, the fake party, the football, etc.,) Unfortunately, the characters were doing their own thing and they were very dull. Rachel and Tag looking for those contracts ; Phoebe going crazy over the fire alarm; Ross and Joey stuck on the roof; Chandler trying to get a very tired Monica to have sex...