10. The One With Phoebe's Birthday Dinner
This episode might rank higher if its very inclusion weren't so debatable. While the previous two Thanksgiving episodes didn't revolve too heavily around Thanksgiving, many don't consider this to be a Halloween episode at all despite both airing and taking place on the holiday. Aside from the opening scene and the appearance of a few decorations outside of Monica's apartment, the episode lacks pretty much any holiday relevance whatsoever.
Even so, this one's worth adding to your fall playlist if for no other reason than to make up for the general lack of solid Phoebe stories in the series' Thanksgiving episodes. Joey's lone presence at Phoebe's birthday dinner for the bulk of the episode shines a spotlight on just how great these two are as a duo, and it's a shame that even this episode doesn't give us more of them.
That said, the other characters' coupled-off stories include some great moments, such as Monica's sexual manipulation of Chandler and one of the cutest-ever interactions between Ross and his mother.
Most notably, this might be one of the few episodes actually improved by its occasional errors. Phoebe's look of sour disappointment throughout most of the episode makes Lisa Kudrow's two moments of character-breaking laughter all the more enjoyable, first when discussing Monica's breasts and later following a surprise kiss from Joey.