Different World, Different Movies

This is a fictional counterpart of Richard Nixon the Used Car Salesman—in Alternate Universes, your favorite books, movies or music might have never been created or may be different, sometimes even beyond recognition.

When the creators actually did the research, this may be based on What Could Have Been. It may also be related to Celebrity Paradox: In the fictional universe, actors who play the main characters usually don't exist, so other people took their other roles.

Or sometimes it's just done for sake of making a funny pun on a popular real-life work's title.

Comic Books

 * In Ex Machina, created by Brian K. Vaughan and Tony Harris, the main character considers hiring Vaughan and Harris to make a graphic novel based on his life, but decides to go with Garth Ennis and Jim Lee instead.
 * Alan Moore likes playing with this trope. The existence of superheroes in Watchmen and Top Ten leads to superhero comics never gaining popularity; instead, pirate and Slice of Life stories take their place.
 * In particular, the pirate comic that features prominently in Watchmen is meant to represent what Moore himself imagined he'd be writing in this universe instead of Watchmen.
 * In the Marvel Universe, Marvel Comics had lost the rights to Captain America comics, which are now owned by a small company which gets bought by one of Cap's big fans.

Film -- Animated

 * The car-ified versions of earlier Pixar movies appear in the end credits of Cars.
 * The sequel actually combined this with Early-Bird Cameo for Brave.

Film -- Live Action

 * Mixed with Celebrity Paradox in Last Action Hero, in which a boy travels to a world of an action movie. Because the movie's main character is played by Arnold Schwarzenegger, in this world such a person doesn't exist and the main character of The Terminator is played by Sylvester Stallone.
 * The Lost World Jurassic Park has a poster for a film version of King Lear starring Arnold Schwarzenegger. In addition, There's an poster of Jack And The Beanstalks which stars Robin Williams and could be made as a Take That or a In-Joke to a certain movie directed by Francis Ford Coppola.

Literature

 * Regularly played with in the Nightside series, where many stores offer items from alternate histories. This includes alt-history media works, such as Beatles rap albums, pornographic versions of Agatha Christie mysteries, and Orson Welles' epic Batman.
 * In "Swellhead", one of the signs that the characters are slipping into an alternate universe is that the hero finds a copy of 2001: A Space Odyssey written by Ray Bradbury.
 * Idlewild by Mark Lawson has John F. Kennedy surviving his assassination attempt in Dallas and winning a second term as President. Thirty years later, there's a mention of Oliver Stone making a movie titled LBJ, about "The best President we never had".
 * In the Doctor Who Eighth Doctor Adventures, Fitz has assembled a collection of parallel universe Beatles records, including "Feel the Love", their Live Aid song.

Live Action TV

 * In Fringe's featured alternate universe, there's quite a bit of this.
 * Many DC Comics properties are slightly different - Green Lantern and Green Arrow are Red Lantern and Red Arrow, Jonah Hex is a member of Justice League International instead of Guy Gardner, Superman died in Crisis on Infinite Earths instead of Supergirl and, apparently, The Dark Knight Returns and The Death of Superman have switched their main stars, becoming The Man of Steel Returns And The Death of Batman.
 * In Season 4's version of the alternate universe, a character called "The Mantis" fills the same role in pop culture that Batman does.
 * Eric Stoltz is Marty McFly in Back to The Future, obviously based on the fact that Stoltz was the second choice to play Marty in Real Life. (Michael J. Fox was the original choice, but was unavailable because of Family Ties. Stoltz was lined up for the part but a few weeks of filming showed he wasn't right for it, so they tried even harder for Fox.)
 * At one point, Broadway is shown in the alternate universe, complete with a poster for the musical Dogs.

Tabletop Games

 * GURPS Infinite Worlds, set in a world with regular cross-dimensional travel, includes a list of "alternate bestsellers" that were brought home from other Earths. These include a complete Mystery of Edwin Drood by Charles Dickens, an account of the WWII invasion of Japan by Admiral Robert Heinlein, and a biography of Fidel Castro's years as a pitcher in the American League.

Video Games

 * In Grand Theft Auto III and Grand Theft Auto Vice City, you can find posters that advertise the movie BadFellas, which is an obvious parody of Goodfellas.
 * A much publicized gameplay clip of BioShock Infinite shows Elizabeth opening a dimensional "tear" to a 1980s street with a theater showing Revenge of the Jedi (the original proposed title for Return of the Jedi)

Web Comics

 * Darths and Droids has an extended gag about this, in The Rant to comic #50. Star Wars doesn't exist in the players' universe, because the comic wouldn't make sense if it did. So various other Star Wars-influenced things are also different, including Darths and Droids itself, which has become Wands and Warts, a Harry Potter comic. There's a link to a mockup of a Wands and Warts page, with a similar rant at the bottom, except that it links to a comic based on The Sound of Music (Notes And Nazis), and so on and so on.
 * Which comes around full circle in the Pirates of the Caribbean comic, Barnacles & Bilgewater, where The Rant actually makes reference to Star Wars.
 * A VG Cats comic shows a world where Aerith and Leo are dogs who play games such as Minor Konflict and the Shadow the Hedgehog-esque Yoshi the Dinosaur.
 * In Catena, the characters (who are anthropomorphic cats) go to see the musical People.
 * In Manly Guys Doing Manly Things, Commander Badass claims that he was once sent back in time to win the Vietnam War for America...only to then be sent back again to undo his actions because a world without the Rambo movies was too bizarre.

Web Original

 * Fear, Loathing and Gumbo on the Campaign Trail '72: The timeline periodically refers to which films won that year's Academy Awards. At first they're mostly the same films as our timeline, but as the years go on and changes accumulate, more and more different films appear—often reflecting the different influences from the changes in the global situation. The timeline also mentions changes in television: for example, Gene Roddenberry made "Star Trek: Phase II", Star Wars was never made after George Lucas died in a car crash, and All in The Family had a different arc based on the increased poverty in this world's version of the United States.
 * Look to the West: No media after about the 1760s is the same as our timeline's. Periodically examples of literature, art and music are discussed. One major change is that, because Wolfgang Amadeus Mozart became a military leader rather than a musician, classical music has not had the influence of his works. Architecture is also very different: the alternate French Revolution favoured utilitarian buildings rather than neoclassicism like OTL, so neoclassical architecture is less discredited, and increased trade with India and China means there is a fashion in Europe in the 1820s for emulating Oriental styles of architecture. Speculative Fiction, here known as paracthonic romance, has different traditional tropes and genre boundaries. For instance, what OTL would consider "hard" sci-fi is instead considered a branch of speculative romance (i.e. alternate history) rather than scientific romance (i.e. science fiction).
 * A World of Laughter, A World of Tears: Due to the increasing conservatism of President Disney's America, many filmmakers and musicians flee to Europe, leading to a much different pop-cultural development. Orson Welles encounters Ed Wood, hires him, and films a version of Faust, which becomes a massive success; the Quarrymen are a jazz-fusion combo; Motown takes off in England...
 * Fenspace has this twice over -- firstly, because it's an Alternate Universe that diverged from our timeline in 2006 different TV shows and movies get made; and second, a bunch of Dimensional Travelers showed up and dropped off an archive which had, among other things, samples of shows and movies from 20 or 30 other universes.