The One With The Football (Season 3, Episode 9)
The Story: While watching a Thanksgiving Day football game together, everyone decides to play a game of their own — despite Monica and Ross’ reluctance due to a mishap at the sixth annual Geller Cup.
More than anything, this episode exemplifies what Friends (and many other pre-bingable sitcoms) are famous for "bottle" episodes. That is, it is a self-contained narrative that, although referencing broader ideas and arcs going across the series, stands properly on its own two feet. Or, at least, it does when it isn't being addressed. There are lots of amusing throwaway bits (such as Chandler and Joey's mutually futile attempts to seduce a random passerby), but Monica and Ross' heated competition takes the prize.
Link: https://www.metacritic.com/tv/friends/season-3/episode-9-the-one-with-the-football
