Stock Sitcom Grand Finale

Sitcoms can be formulaic. Often this applies not only to regular episodes but to the Grand Finale. One would generally think that the writers would want to pull out all the stops and get creative to create a truly one-of-a-kind ending to the show that their fans have been following all this time. However, that's not always the case.

It goes like this: At the end of the final episode all the main cast are standing in the living room. It's quite likely (but not required) that the family or at least some of the main characters is moving, indicating that this is the last time they'll be together in this place. They have a touching conversation about all the good times they've had (levels of Narm may vary here). Bonus points if they hang a lampshade on a Running Gag or Hand Wave a bit of Fridge Logic that fans have been puzzling over. Then all the main cast exit through the main door. One person (generally, the main character) pauses in the doorway, takes a long, soulful look around the room, then slowly turns to follow the others. The camera will either linger on the closed door or pan slowly across the room.

Variations include:

A Flash Back to the first episode.
A review of notable moments in the series. It may be a Montage lasting a few minutes, or possibly the whole episode can be a Clip Show.
A moment after the door closes on person comes back in to do one last thing, such a turn off the lights or grab a memento that they almost left behind.
A moment after the door closes one person comes running out of a back room calling out, "Wait for me!" This is generally Played for Laughs.

This is a sub-trope of Grand Finale

As an Ending Trope, Spoilers ahead may be unmarked. Beware.

Examples of Stock Sitcom Grand Finale include:

Live-Action TV

The end of The Mary Tyler Moore Show had the cast (who were all fired from the station, except Ted Baxter) in a group hug, then one by one they left the office while singing "It's a long way to Tipperary." Mary was the last one out, took a look, and turned off the lights. Then the stars came out for one final curtain call. Note that, as the oldest entry on this list (the series finale aired in 1977), this is also the Trope Maker.
The Nanny has Fran looking at the make-up case she carried in the first episode with a Montage of clips from the series before making the slow exit. Then she comes back in and opens the bathroom door to get Yetta.
The Fresh Prince of Bel-Air ended with Will taking one last look at the empty living room and then turning off the lights, while Carleton was still using the bathroom upstairs.
Growing Pains
The Cosby Show switched things up a bit. At the end of the show, Cliff fixes the previously broken doorbell as it rings a snazzy jazz tune. Cliff and Claire promptly start dancing along, and then the two actors walk off the set and out of the studio to a standing ovation.
Friends ended with Chandler and Monica leaving the apartment the cast spent most of their time in. The episode ended with a shot of the empty apartment.
Boy Meets World had a variation. The main characters who were moving said goodbye to the family at the house, and then went to the classroom to finish it up with Mr. Feeny.
Full House had the entire cast sharing the narmy conversation in the living room (including bringing in Steve as a Call Back), but faded to black without showing the cast exit.
Not a sitcom, but Babylon 5 had creator JMS play a caretaker character who turned off the lights on the entire station before it blew up.
Cheers had Sam stay behind to close the bar. Instead of leaving through the front door, he walks to the back.
News Radio had Mr. James retiring and setting up a new station in New Hampshire. He asks Dave for one employee to take with him, and Dave without hesitation choses Matthew. The others feel sorry for Matthew and one by one they all join Jimmy. The episode ends with Dave alone at WNYX ...except for Matthew, who secretly stayed behind. It is implied that Dave later went with the others to get away form Matthew.
The final episode of Seinfeld was a two-parter that tried to incorporate as many previous guest stars as they could, and ended with the cast in jail, repeating dialogue from the first episode, and then Lampshading it.
An episode of Quebecer show "Dans une galaxie pres de chez vous" had such a scene before everyone disembarked the ship, with the captain lingering behind. This troper doesn't really remember, but she thinks they all got back on board and left again on the ship instead of staying on the planet.
Moesha also had the "door close" ending with the closing of The Den.
Scrubs parodies this idea in one of JD's daydreams, although it wasn't the finale, in which JD imagines leaving the hospital like they do at the end of sitcoms. He looks around and turns out the light just before going out the door, which turns out all the electricity in the entire hospital, causing a big panic as all the life support and vital equipment stopped working.
Home Improvement, with the entire family (minus Randy) sitting around the living room, preparing to leave it for the last time, and flashing back to various episodes.
Mystery Science Theater 3000 uses this, but not as the final shot. In Danger: Diabolik, the great experiment is finally and definitively ending, so Pearl, Observer, and Bobo pack their belongings, line up new careers, and prepare to go their separate ways. In the final host segment, they're hugging and singing together in the now-vacant Castle Forrester; Pearl turns to the camera and says "Move on, Mike. We have," before disconnecting it. However, the episode then returns to Mike and the robots, and ends with a Time Skip to show Where Are They Now.
The Barney Miller finale ends with Barney looking around the now-abandoned squadroom, stopping at various desks to reminisce about long-departed characters (shown via old clips), and then turning out the lights.
Happy Days, rather oddly, ends with Howard Cunningham interrupting Joanie and Chachi's wedding to thank the viewers directly for "being part of our family".
That '70s Show ends with a shot of the empty Forman basement, after the kids head upstairs to ring in the New Year with the parents. We hear the voices counting down the final seconds of 1979, followed by an abrupt cut to a shot of the show's license plate title logo (now sporting a 1980 tag) and then the closing credits.
Parodied in the season 1 finale of Community.

Web Original

Red vs. Blue pops up as a web example, with Church finding himself in a memory of the first episode, waiting for Tex to find her way back to him.