Star Wars did its own spin on this with the limited comic seriesStar Wars: Infinities, each story exploring how such a change would affect each of the Original Trilogy films. In specific...
In A New Hope, Luke fails to destroy the Death Star because one of his torpedoes malfunctions. As a result, the Empire catches several Rebels trying to escape Yavin, including Leia, who Vader trains as his apprentice. In the meantime Luke trains with Yoda, and after five years he confronts Vader and Leia, ultimately ending when Yoda Colony Drops the Death Star on top of the Emperor's palace.
In The Empire Strikes Back, Luke dies of exposure on Hoth, leading Han and Leia to seek Yoda. Lando doesn't betray Han, getting Cloud City destroyed. C3PO ends up in Vader's hands and finds out about Dagobah, leading him to confront Yoda (and get into a mental battle against the spirits of Jedi passed like Qui-Gon and Mace). Vader gets killed by a surprise attack by Han, leaving him and Leia to rejoin the Rebels and fight the Emperor.
In Return of the Jedi, C3PO gets disabled by accident, forcing Leia to reveal her identity to Jabba and allowing Boba Fett to escape with Han in the confusion. Yoda dies before Luke can hear his final message, meaning Luke (and the Emperor) sense his death and Luke gets captured leaving Dagobah. Meanwhile, Leia mounts a rescue mission to save Han, but he's become permanently blind. Because the heroes don't befriend the Ewoks, they attack both sides at the shield generator, meaning Han and Lando have to take it out. Luke and Leia manage to redeem and rescue Vader, who dons a white costume and joins the good guys in hunting down the Emperor.
In a nice touch, the highly trained Force users can sense that things are not as they should be, though they don't quite know what is going on. They just know the Force is going nuts. Also interesting, each scenario still results in the forces of Good defeating Evil, just with the plots changed significantly. (In fact, each ending may have actually been betterif slightly bittersweet.)
There was also a script by Peter David where the point of divergence was that the first robot Luke picks up from the Jawas doesn't blow a gasket, and thus he never buys R2-D2 and never hears Leia's recorded message. According to David himself, the script was not picked up because it did not fulfill the requirement that the Empire has to lose in the end, regardless of whatever else happens differently. They also objected to the ending, which saw Leia becoming a Sith Lord and taking on Luke as her consort (since neither one knew they were related).
Star Trek has the series The Last Generation, where the assassination plot from Star Trek VI succeeded (thanks to Captain Braxton), resulting in the Klingons dominating the galaxy as far as the Next Generation era, with most of the TNG cast as scarred resistance fighters, Worf as the leader of the Klingon Empire, and Sulu using the Excelsior to make hit-and-run raids on the Klingons as "the Silver Ghost".
In the Star Trek (2009) comic series made by IDW, the storyline "The Q Gambit" has everyone's favorite omnipotent being yank the 2009 crew from their timeframe to around the time where the Dominion War should take place, showing off a universe without Kirk's influence. One where the Klingons conquered Earth, the Dominion is close to taking over the Alpha Quadrant and the last bastion of hope is Benjamin Sisko and a motley crew of others.
Tom Strong had an entire story arc about the alternate reality where, due to a two-minute delay, their ship to Attabar Teru encounters slightly different waves. Where in "our" universe, the sailor Tomas Stone died when the ship wrecked upon reaching the island, in this one it was Sinclair Strong who died. Consequentially, everything changes: long story short, Tom Stone grows up to be less powerful or scientifically minded than Tom Strong, but much more emotional and compassionate. He ends up reforming nearly all of his enemies, and with them creates a virtual utopia until destroying it by sleeping with his best friend's wife Dhalua, who is Tom Strong's wife in "our" universe.
The comic dabbled with this early in its run. In issue 50, we're shown one universe where Will refuses the Heart of Kandrakar. However, the girls still become Guardians - the Heart's very insistent.
There was a one-shot focusing on Cornelia, Caleb and their relationship had they remained together (in this universe, they broke up after dealing with Nerissa). One story had Cornelia leaving the team and joining Caleb in Meridian. Though she's happy, it doesn't last long and, soon, the girls confront her and convince her to return. The only major difference here is that, where the main universe had Orube replace Taranee, here not only does she replace Cornelia, she and Will end up swapping powers so that Orube's leader and Will control Earth. The other story had Caleb join Cornelia on Earth. His Fish out of Water-ness is so bad that it ends with Irma shot by her own father (by accident) and the girls' identities exposed.
The third story arc of My Little Pony: Friendship Is Magic lampshades this trope - the story is driven by the fact that Big Macintosh needs nails to repair the gazebo, forcing him into town and the various antics that occur there. The trope is hammered in by the branding of the empty nail box: "For Want Of" Brand Nails.
During a point in Sonic the Hedgehog (Archie Comics) where Knuckles had joined the Dark Legion in an attempt to rescue his friends, family and the people of Echidnaopolis from the Quantum Beam the Legion used on them, he decided to use his awakened Chaos powers to undo certain points in Echidna history. First, he tries to destroy the White Comet, only for an freak earthquake to destroy the city. Then, he hypnotizes the High Magistrate of Echidnaopolis to allow Dimitri and Edmund's plan to lower the island to go through, only for Angel Island to crashland in the attempt. His final attempt is to stop the assassination of Edmund, only to start being roboticized due to no Brotherhood of Guardians to try to keep Robotnik in check. Ultimately, Knuckles decides to just undo the effects in the present. Interestingly, the events also altered the rest of Mobius, though they show four alterations while Knuckles preformed three events. The first change shifted them into the Sonic the Hedgehog: The Movie universe, the second change was one where Mobotropolis and the Brotherhood were allies and the coup was stopped by Tails' dad. The third change shifted them into the world of Sonic the Hedgehog (SatAM) and the final change is the alternate universe where Sally died at the end of EndGame.
The main plot of The Fox Hunt is kicked off due to Dream Demon sabotaging Mr. Smile's efforts of turning her and The Fox's old hometown into a Water Shed while leaving a pattern of mushrooms in The Fox's image. That last bit is what causes Mr. Smile to put a hit out on him, which leads to pretty much everything else that ends up happening.
IDW's Deviations one-shots will focus on five franchises and major turning points:
For The X-Files, we see a world where Fox Mulder was kidnapped by aliens and its his sister Sam working with Dana Scully. Fox is actually still alive, but a chance mysterious encounter with him ends up ending Scully's skepticism of the unknown.
For G.I. Joe, it's a world where Cobra uses the M.A.S.S. Device to take over the world. Cobra Commander gets really bored and wants to put things back together.
For Ghostbusters, it's a world where the four didn't Cross the Streams, leading to a New York ruled by Gozer. Gozer doesn't like being stuck in the Stay Puft Marshmallow Man's body and tries to get out of it all.
For Teenage Mutant Ninja Turtles, it's a world where Shredder succeeds in brainwashing the brothers.The four break free, but the incident leads to just about everyone dying.
For The Transformers, we see a world where Optimus Prime and Megatron's ultimate battle in The Transformers: The Movie ends with a victorious and still alive Optimus, as Hot Rod is prevented from aiding Optimus. Without Megatron to bargain with Unicron, the dying Decepticons are killed by Unicron. The Autobots fly off to confront Unicron, but Hot Rod's still impulsive behavior causes the deaths of Ultra Magnus, Arcee, and Perceptor during the space flight. Meanwhile, Optimus overthrows the Quintessons, rescuing Kranix before picking up Hot Rod and Daniel. Ultimately, Hot Rod still uses the Matrix to defeat the World Destroyer, but because of Starscream's incompetence once he becomes leader of the Decepticons, the villainous group is crushed once and for all.
2017 is set to have five new stories:
X-Files returns to its altered timeline.
Star Trek gives us a world where Earth has become a brutal penal colony when the Romulans are who initiates First Contact with Earth, not the Vulcans.
Orphan Black has a world where Sarah saves Beth from her suicide.
Judge Dredd revisits the storyline "Cry of the Werewolf" and asks what would happen if Dredd was never cured of his lycanthropy.
Mighty Morphin' Power Rangers (Boom! Studios) reveals that the mysterious Lord Drakken is actually a Tommy Oliver from a universe where, after Jason destroyed the Sword of Darkness, Tommy bailed on the team and went back to Rita on his own accord. They conquered the world, killing most of the Power Rangers, the Alien Rangers and the Phantom Ranger with Tommy stealing and fusing the White Ranger power with the Green Ranger power.
Rick and Morty (Oni): When Summer thinks her popular alternate is popular because she's lesbian, Rick sets her straight: Popular!Summer is so well-liked because her version of Beth is allergic to red wine. Thus, this version of Summer grew up with a mother who wasn't a drunk and was incredibly supportive of her daughter, and has a lot more confidence and self-esteem as a result. Furthermore, Morty doesn't exist in this dimension since Beth never drunkenly allowed Jerry to impregnate her again.
It's strongly implied at the end of issue 1 that the Lost Light was such an event; seemingly minor for anyone outside of the crew, but actually have massive consequences. The message from the future was sent to prevent this but failed due to no one hearing it.
In issue 35 Brainstorm's meddling in the past creates an alternate timeline where the Decepticons were never able to overthrow the Senate. As a result the Great War never took place, the Functionist Council eventually took control of the Senate instead, Minimus Ambus never became Ultra Magnus, Dominus Ambus never disappeared, Chromedome and Rewind never got together, functionism and ratioism is planetary law on Cybertron, the Black Box Consortia pressured Cybertron into selling Luna 2, and the Lost Light crew never met each other to go on their quest.
On a more comedic note, issue 37 reveals that the entire Autobot-Decepticon war started...because Tailgate wanted a curly straw. So here's what happened: When travelling through the past, the crew ended up at the bar where Megatron, who had been simply speaking out against the corrupt Senate at the time, is wrongfully arrested following a bar fight, thus convincing him to go full-blown revolutionary. While waiting for Megatron to show up so they can prevent Brainstorm from stopping this event from ever happening, Tailgate asked Rung to get him a curly straw for his drink, but Rung accidentally bumped into another patron, causing him to spill his drink, and directly leading to said bar fight breaking out.
In the universe of The Last West, the failure of the Jughead nuclear test led to America abandoning its quest for the atom bomb, which altered the course of the war and thus history itself.