After the family takes their usual places on the couch, the couch rises into the air and is actually part of the tendril of an anglerfish (which bears a striking resemblance to the one from Finding Nemo), which eats the family.
The family runs into the room and take their usual places on the couch. Nothing happens. Lisa then says directly to the viewers "What, can't we sit on the couch without something happening?" Homer then gets impaled by a spear and yells, "D'oh!"
The family, dressed as hockey players, with cuts and scrapes, skate into the living room and skate around the couch. Homer is carrying the Stanley Cup with Maggie sitting in the bowl. (There was a lockout in NHL that season)
The family enters the living room and sits on the couch like normal. "Homer" then pulls off his face, revealing himself to be Sideshow Bob. Bob pulls out a knife and chases Bart out of the living room. (some airings use an alternate version where after Sideshow Bob gets his knife out, Bart starts to panic & runs out of the living room screaming with no chase happening. Also, some airings use the Duplicate Family couch gag instead)
The family sits on the couch, only to have a spit comes through the wall and the floor open up to reveal fire down below. The couch and family begin rotating over the fire. Marge's hair catches fire and the boat painting falls off the wall.
Several toy forms of transportation come into the living room, only to change Transformers-style into the family. Homer is Optimus Prime, Marge is Skyfire, Lisa is Hound, Maggie is Bumblebee, and Bart is Jazz.
The living room is an almost fully assembled jigsaw puzzle, with only the pieces with the family members' heads needing to be placed. The person completing the puzzle places all the heads on correctly except for Homer and Maggie, after which the former fixes them.
The family enters the living room through a metal detector, except for Homer, who sets it off. After four failed attempts, Homer (who is now stripped down to his briefs) is detained by a security guard who is inspecting Homer with a handheld scanning wand.
The family enters the living room and takes their places on the couch. Then, an on-screen TiVo style menu pops up asking if the viewer would like to delete or save this recording. "Delete this recording now" is selected and the screen goes blank.
The family runs in to sit on the couch, but it turns into a monster and chases them out of the house. Everyone's couches come to life and start attacking and swallowing the people sitting on them; after Hans Moleman, Sherri and Terri, Lou and Eddie are seen getting attacked by couches, Professor Frink is attacked by a futuristic flying couch with laser weaponry, and Moe is attacked by the booths in his bar, but fights quite well with his shotgun. Homer takes refuge in a store called "Couch World", where he is piled upon by dozens of couches (an unusually long couch gag, as it runs for exactly forty seconds)
The Simpsons sit on the couch as normal and a camera flashes, setting off a series of family portraits. In the 2006 and 2007 portraits, they all look the same. In 2008, Homer is missing and the family is wearing black. In 2009, Lenny has taken Homer's place and Bart and Lisa both begin puberty. In 2010, Carl has taken Marge's place and Lenny is still there. In 2011, Marge is back, but Lenny is gone and replaced by Jimbo Jones. In 2012, Homer is back, but is now a robot. In 2013, every member of the Simpson family is a robot.
In a parody of the Bonanza opening, a map of Springfield burns away to reveal the family on horseback in the countryside. The couch is nowhere to be found, however. The Bonanza-like music that is heard continues over the "Created By/Developed By" TV credits.
The family enters the living room only to find their access to the couch has been blocked by laser beams. They work their way through the laser beams and sit down. Then the beams shut off and Homer's head drops to the floor.
The family (played by the same live action actors and actresses from the live action opening that precedes this) sit on the couch, and the TV credits are superimposed over the live action TV screen. (Subsequent airings on Fox and FXX have a repeat of the Kebab Grill couch gag)
The couch is replaced by four wooden stools. An instrumental of Pop Goes the Weasel plays as the family plays musical chairs. When the music stops, everyone, except for Homer, sits down. Homer groans in disappointment.
A vending machine filled with snacks looking like characters (including the Simpson family) from the show appears instead of the couch. Ralph Wiggum comes in, selects a Homer figurine, and bites the head off before leaving.
The family sits down and gets moved across the floor in a car wash, where they get sprayed with water, squirted with hot wax, and scrubbed with brushes. Marge's hair turns puffy, Maggie's pacifier turns up missing, and everyone looks sad as three men wipe them dry and puts a new pacifier in Maggie's mouth.
In a Macintosh-esque computer window, the Simpson family is drag-and-dropped onto the couch, which is then drag-and-dropped into a trash can. The mouse pointer then goes to the "File" tab of the window and clicks on "EMPTY TRASH".
The family (in Christmas attire) sits on the couch, and the camera pulls out to reveal they are in a Christmas decoration which is on a Christmas tree. Santa's Little Helper and Snowball V rest nearby.
Homer evolves from a single-celled organism which continuously divides to a more complex organism—first as a jellyfish, then a common fish that nearly escapes the clutches of an octopus that looks like Mr. Burns. Getting out of the ocean, Homer evolves into a prehistoric lizard that extends his tongue to snack on an insect that resembles his power plant coworker, Lenny. Homer then evolves into a slightly larger lizard with a scale on his back that sees a pterodactyl resembling Principal Skinner's mother, Agnes, flying overhead. Homer then evolves into a rat that gets chased by a tyrannosaurus rex resembling Bart, who then gets into a battle with a stegosaurus resembling Lisa. Homer hides in a hole just before a large asteroid crashes on Earth, wiping out all dinosaur life. Homer comes out of the hole, passing the skeletal remains of T-Rex Bart, before changing into a sloth, then a monkey as he approaches a jungle, becoming more apelike upon swinging through the trees. Leaving the jungle, a brief Ice Age occurs as he evolves from a Neanderthal, to a Cro-Magnon, to an upright walking caveman. Caveman Homer passes by Moe (who is also a caveman), who then devolves into a rat creature. As Homer continues walking, he evolves into men from different historical eras (a nomad from the Middle Ages, a Spanish explorer, a Pilgrim, and a 19th-century intellectual) until he finally evolves into his modern self and enters the house, stepping over Santa's Little Helper. With the rest of the family sitting on the sofa, Marge asks him "What took you so long?" Homer can only give an exhausted sigh of relief. (This is the second longest couch gag as it runs over 1 minute long)
The family comes in and sits on the couch. A second family comes and also sits on the couch. Then hundreds of multiple families come in, and the second story windows and chimney overflow with them. Homer shouts, "Hey, don't shove!"
The entire opening sequence is changed to show a ruined Springfield being rebuilt in the aftermath of The Simpsons Movie. As construction work goes on around them, The Simpsons join Plopper the pig on the couch to the tune of the "Spider Pig" theme. Homer holds him and says "My summer love".
The living room is made of Lego bricks and the family members are built one by one out of Legos. Homer shouts, "Woo-hoo!" when a 1x3 Lego brick is put on his head, and "D'oh!" when a black 1x1 Lego brick (representing his two strands) is placed on his head instead.
The family sits down as normal, except Maggie is missing. Homer looks to the empty space where Maggie is, then gets lifted by a giant Maggie as the camera pulls out to reveal the living room being part of a dollhouse and the family as the dolls that live within. Maggie puts the miniature Homer in her mouth and sucks it like a pacifier.
The Simpson family is already sitting on the couch. The camera zooms out to reveal a sentence that says, "Ceci n'est pas une couch gag" ("This is not a couch gag" in French). The camera zooms out again to reveal the family and the couch as a painting in a museum. Mrs. Vanderbilt and a man look at it.
The Simpsons go through the sets of The Honeymooners (from the 1950s), The Dick Van Dyke Show (from the 1960s), The Brady Bunch (from the 1970s), and Cheers (from the 1980s). During the Cheers segment, Sideshow Bob enters in reference to Kelsey Grammer's character in Cheers, the family run out screaming and end up at the couch in their show (from the 1990s/2000s) with a sigh of relief.
The Simpsons come in and find their couch beaten and torn. Funeral music plays as they bury the couch in the backyard. The Simpsons then visit a ranch to pick out a new couch. The Simpsons sit on a black and white spotted couch, which throws Homer off it. The scene then cuts to the Simpsons in their living room, sitting on their new couch. Homer is in a body cast and turns on the wall-mounted flatscreen TV.
The Simpsons are a meal at a fancy restaurant (Homer is a garden salad, Lisa's face appears in a bowl of soup, Marge is a plate of spaghetti and meatballs, Bart is a T-Bone steak, and Maggie is the mint that comes with the restaurant bill), which Comic Book Guy eats. After he wipes his mouth with a napkin, a stain appears that resembles the Simpsons sitting on the couch.
The screen is white. A cartoon left hand flips an animation cel that has eyes on it, flips another that has Homer's skeleton sitting cross-legged, flips another that has Homer's stomach and a can of Duff beer on the lap, flips another that has Homer naked, another where the rest of the family are fully clothed and sitting in mid-air, and another where the Simpsons are in their living room and sitting on the couch. Marge notices Homer is still naked and pulls down an animation cel that has Homer's clothes.
The living room is covered in thick, jungle plants. The Simpsons slash their way through in order to reach the couch, and find an ape version of the Simpson family already seated. The ape-Simpsons hoot and screech, scaring off the human Simpsons.
There's an Olympic-sized pool leading to the couch. The Simpsons take their places on the marks and swim to the couch once a starter pistol goes off. Marge is first, Lisa's second, Bart is third, and Maggie is last. The family looks around, wondering where Homer is. Cut to a shot of an unconscious Homer floating facedown in the pool.
The living room is the seating area in the Colosseum during the era of the Roman Empire. The Simpsons (dressed in togas) rush to an empty space to sit down. The sounds of a gladiator match can be heard offscreen. The audience cheers as the head of a gladiator flies into the audience. Bart catches it.
A large marble rock is in the living room where the couch should be. A stereotypical French sculptor quickly chisels out a statue of The Simpsons sitting on the couch. The sculptor then turns the statue of the Simpsons into a statue of a Civil War soldier on a horse.