Many fans of Don Bluth films disregard the DTV sequels of his movies (which Bluth had nothing to do with). This is especially true of the series of sequels to The Land Before Time because any subtext is now gone and they are now musicals, when the original was not.
Ignore ALL the sequels. They're all results of turning a beloved movie into a Cash Cow Franchise anyway.
Accept the original and the first sequel only. No heart after that.
Accept the movies up to IV and ignore the rest. In The Mysterious Island, the production team radically altered the environment, meaning that the Mysterious Beyond looked like just about anywhere else in the world.
Accept the first four sequels, but disregard the rest, due to a writer switch that was perceived to have made things go downhill after that quality-wise.
Accept the movies up to VII. Films V-VII each have their good points, and interesting guest characters, but VII would be the last film to have no non-conspicuous computer graphics.
Accept the movies up to X. We see Ducky and Spike's relationship get some interesting attention in VIII, we get a reprise of the best song from V in IX, and in X we finally meet Littlefoot's dad. But after this, the movies are more sitcom-like in nature, with multiple gag plots, characters like Cera's dad acting wildly out of character, and even more explicit morals than people claim the first nine sequels have.
Accept ALL the sequels. The Land Before Time is The Land Before Time, no matter what it is.
Accept ALL the sequels and the TV series.
Or any variation of the above.
Fans of Don Bluth's The Secret Of NIMH disregard its truly awful Lighter and Softer musical sequel Timmy To The Rescue. Aside from the change in tone, it doesn't help that the sequel kludges continuity with its prequel, claiming that Nicodemus was a prophet and that he claimed that a son of Jonathan Brisby would become a hero (Nicodemus wasn't a prophet and he made no such claim). While refusing to even acknowledge it as canon, most fans of the original still lament that there isn't enough Brain Bleach in the world to wipe the sequel from their memories.
The third and fourth An American Tail movies are on the receiving end of this trope. The latter gets this for being boring.
Fievel Goes West is on a Broken Base. It's either fun or stupid, depending on who you ask.
The continuity of Disney's classic characters (Mickey, Donald et al.) depends on who you talk to, given they show up in different time periods and appear in works aimed at different age groups.
Disney's Direct to Video sequels and spin off cartoons of its movies are often disregarded by fans for reasons including resetting Character Development, Character Derailment, and are generally found to be inferior to their source materials.
Many fans of the first Cars movie deny the existence of the sequel Cars 2 or the spin-off movie Planes, and some will accept Cars 2, but ignore Planes and the Mater's Tall Tales animated shorts, or any combination of the above.
The Ice Age sequels are either love it or hate it for fans of the first film, but many who enjoyed the first three films agree on pretending that that the fourth film, Ice Age: Continental Drift never happened.
Good luck finding a BIONICLE fan who pays attention to the Retcons about how Matoran and every other living thing in the "Matoran Universe" are supposed to be mindless automatons and how being individuals with personality was just a glitch in their AI. Similarly, paying attention to the retcon inducing universal Asexuality and No Hugging, No Kissing is a rarity, all the more so since the Mata Nui Online Game and the Adobe Flash animations, the early material establishing the Matoran's capability to love, is widely considered some of the fandom's favourite parts of the story.
Amongst the people that remember that this movie is a Disney film, or that it even exists, Home on the Range gets this treatment. It's liked by few Disney fans. People act as if Brother Bear was the last traditional animated film until recently.
Animated TV Series
There are Ben10 fans that rejected the sequel series Ben 10: Alien Force, possibly because of retcons to Gwen and Kevin's powers and turning Kevin into a good guy.
Speaking of Ben 10, there were fans who inverted the trope and held the episode "Goodbye and Good Riddance" (where Ben returns to his home town at the end of summer vacation and gets outed as being a superhero) as the show's finale as opposed to "Secrets of The Omnitrix", and that's just the original series.
Several longtime fans of the first three series of the Ben 10 franchise (the original, Alien Force and Ultimate Alien) don't consider Omniverse as canon due to its change of style, redesign, heavy use of comedy and absence of the creators Man of Action.
The Critic: Most fans of the TV series were disappointed with the webisodes that followed a few years after the show's cancellation. This fan review should provide further explanation.
Ren and Stimpy's "Adult Party Cartoon" version, for being one of the most despised versions among fans, showing the Black Comedy and Vulgar Humor of this cartoon turned Up to Eleven, to the point that many find in it as completely disturbing. You know it's bad when even the Games Animation episodes (which are also considered fanon discontinuity for making Ren more of a jerk than comedically allowed) are now considered better.
Anything after the Channel Chasers movie of The Fairly OddParents, which wraps things up with a bittersweet flash forward to Timmy as an adult, or anything after Poof's birth, depending on whom is asked.
Some fans of My Little Pony: Friendship is Magic want to forget all episodes that no longer receive much creative input from Lauren Faust. The cut-off point varies between different groups. Purists would disregard anything after "Returnof Harmony" as Lauren began to wind down her involvement with the show soon after, while others in this circle only regard certain points in the middle of season 2 to be the start of discontinuity due to Lauren still providing script input for a fraction of the season before her departure. Although there are some fans who don't even like to acknowledge some Season 1 episodes like Swarm Of The Century and Feeling Pinkie Keen.
Due to the tendency for G4 MLP merchandise to significantly deviate from the show, fanon discontinuity may also occur between fans of the show and fans of the merchandise.
This commonly occurs with toys in particular. On one hand fans of the show often disregard details and backstories of the toys as they are thought to be written by third parties who seemingly have spotty knowledge of the show, while fans of the toys view the toy line's attempts to be more show accurate as moves to pander to more casual adult fans of the show, among other reasons.
Canon of official books and comics specifically targeted at children are also ignored by adult fans of the show for similar reasons, especially the German variants, which are notorious for their bad art and storytelling.
Gargoyles season three, 'The Goliath Chronicles'. The writing staff changed completely and had no grasp of series continuity. Most noticable in the season's second episode, 'Ransom', where Fox is easily restrained by a human thug while her son is kidnapped and later reduced to crying in a chair, clutching his teddy bear, when in the previous seasons, she was established as a deadly ex-mercenary who fought and nearly defeated a nigh-all-powerful Fairy King with previously-unknown magical powers a few hours of giving birth.
Greg Weisman himself points this very thing out when he's criticizing this episode, which make sense considering how much effort the original show made to have strong and likable female characters.
G.I. Joe fans often do not count the DIC series as canon because of its inferior writing.
Same with Mr. Garrison's sex change, as many thought it wasn't funny, added nothing to his/her character, and was more a Writer on Board moment than anything. Even though it eventually got the reset button treatment in "Eek! A Penis", many fans feel the whole "Mrs. Garrison" arc was pointless and shock value only for the sake of such.
For quite a few fans, the Tom and Jerry episodes directed by Gene Deitch never happened. Simply put: If it didn't come from Hollywood USA, it's not a Tom and Jerry cartoon, though the Chuck JonesTom and Jerry cartoons are somewhere in the middle of being as beloved as the original Hanna-Barbera Tom and Jerry and being despised like the Gene Deitch incarnation. Even Chuck Jones says he doesn't care much for the Tom and Jerry cartoons he did in the 1960s (but it did help him with The Grinch Who Stole Christmas, so it's not all bad).
Fans of Dexter's Laboratory usually ignore the 3rd and 4th seasons due to the original creative staff leaving and the show becoming remarkably different as a result. It helps that the second season finale was intended to wrap up the series. There are some willing to accept the TV movie Ego Trip as canon, given the original creator's involvement in making it.
Similarly, fans of The Powerpuff Girls disown everything after "Power-Noia" when Chris Savino took over as producer (creator Craig McCracken left to start up Foster's Home for Imaginary Friends). The nadir was the episode "West In Pieces," which won a special juried Emmy. The series took a jarring shift in tone, turning from a lighthearted action show into a crude gag comedy where the main characters just so happened to have superpowers.
The episode "Epilogue" also took flak from not just the aforementioned, but even from many fans of Batman Beyond when it revealed that Terry Mcginnis was actually the biological son of Bruce Wayne, courtesy of well-meant meddling from Amanda Waller. Shipping wars was another major reason for the Broken Base, as "Epilogue" establishes that Terry's relationship with Dana (unpopular with many fans) is stable and long-term, implying they will marry, in stark contrast to fanon that had them breaking up shortly after the series ended.
If you want to keep fans of Family Guy happy, do not acknowledge the episode "Not All Dogs Go To Heaven" in any way. Though most reviews pegged the episode as "So Okay, It's Average" (they liked the "Stewie hangs out with the Star Trek: The Next Generation" story, but feel that the "Meg converts to Christianity and Brian stops it so he can drink again" main story wasn't very good), a lot of fans have ranted and raved over the Unfortunate Implications about religion and atheism (even though it does have some good messages about fundamentalism and irrationality in religion being dangerous). Even the show writers had to apologize for it (and for turning Brian into an atheist by having characters rag him for it in later episodes, most famously, when Quagmire verbally smacked him down for his douchebag, freeloading attitude, his overinflated ego, and how much of a boring, alcoholic hypocrite he really is). In fact, a lot of season seven episodes (barring "Road to Germany"note The episode where Brian and Stewie use the time machine to go back to 1939 and save Mort Goldman from the Nazis and "Ocean's 3 1/2"note The episode where Bonnie gives birth to Susie after being pregnant with her for over 6 seasons and Joe tries to pay for her medical expenses by stealing) is a season that most fans don't want to remember.
Speaking of "seasons no one wants to remember," a lot of fans don't want to acknowledge that Seth MacFarlane revived Family Guy in 2005. They're content in knowing that the show ended either with the "Road to Europe" episode, the "Family Guy Viewer Mail" episode, or the Banned Episode "When You Wish Upon a Weinstein." (Basically everything before David Zuckerman leaving)
Some fans will also include the fifth season simply for the introduction of Brian's then-current girlfriend Jillian, but completely disregard everything after their breakup in "Movin' Out (Brian's Song)".
Some would say that to "Screams of Silence: The Story of Brenda Q.", Now Family Guy has done dramatic episodes before, like "Brian and Stewie," "Dog Gone," some parts of "Jerome is the New Black," and the early episode "Brian Wallows and Peter Swallows," but an episode playing domestic violence for drama coming from a show that isn't afraid to show women being beaten up, sexually harassed, sexually assaulted, and mocked for their appearance and age feels cheap and hypocritical.
The episode Life of Brian in which Brian is run over by a car, is Killed Off for Real, and is replaced by a new dog Vinnie has ripped it's tattered fanbase to shreds.
To be quite fair, not much was known about Skinner before this episode, other than him simply being the school principal who lives with his mother (with a few vague mentions of his days in Vietnam and once part of the B-Sharps). The episode actually gave viewers the first actual back-story for Skinner. The only thing this episode contradicted was his legal name.
Yes, but the audience is supposed to believe that none of Skinner's friends or family noticed that "Skinner" looked and acted completely different, and that none of Armin Tamzarian's friends (he was in a street gang) saw him acting out-of-character or going by Seymour Skinner?
It should be noted that this is played upon in a later episode. At some point in the later seasons, Snowball II dies. Lisa goes through a series of new cats to fill the void, each one also winding up dead through various means. Finally, a cat that looks exactly like Snowball II shows up and is the only cat to survive (albeit by causing a car wreck and subsequent explosion). Lisa joyfully adopts the new cat and says that she will name it Snowball II instead of III because she doesn't want to buy a new cat dish. Skinner, walking by, notes the discontinuity of the situation, to which Lisa responds:
Lisa: I guess it is, Principal Tamzarian.
Perhaps the only episode more reviled for its blatant abuse of canon than "The Principal and the Pauper" is "That 90s Show" which depicts the lives of The Simpsons throughout the 90s, completely ignoring that the events of episodes which aired during the show's earlier seasons took place in the 90s, and completely rewriting canon as a result. This may have been upgraded to Canon Discontinuity in later seasons, since they continue to depict Homer and Marge as having gotten together in the late 1970s into the 1980s.
Another in-universe example: Comic Book Guy refuses to admit that Superman moved to Gotham City, even though someone wrote a comic about it; he says instead it was dreamed up by the author and never really happened.
"The Boys Of Bummer" and "Million Dollar Abie" are disowned for showing abuse to Bart and Grampa respectively that goes beyond Black Comedy.
"Bart-Mangled Banner" for being so heavy-handed against Republicans and conservatives that Seth MacFarlane could rewrite it as a Family Guy episode and no one would be able to tell the difference.
Some fans treat "Lisa The Vegetarian" as this, not for being bad (it's considered genuinely funny), but the fact that they feel this episode started Lisa's eventual Flanderization into a Soapbox Sadie (which it was, due to Paul McCartney only agreeing to do the episode if Lisa stayed vegetarian for the rest of the show's run. The fans saw it as a sign that the Simpsons' writers were kissing the asses of the guest stars they let on the show).
Fans usually ignore the presence of Sideshow Bob's Italian wife and son as seen in "The Italian Bob." Possibly Canon Discontinuity as they're never seen or mentioned again after "Funeral for a Fiend".
"Homer vs. Dignity" is hated by many for sinking to Family Guy-cum-South Park-esque levels of vulgar humor (though the same can be said for a lot of episodes from Mike Scully's era of being show-runner. The panda rape scene crosses the line into Dude, Not Funny! territory with sickening abandon; rarely does a two-minute scene turn an otherwise unremarkable episode into one of the most-hated in the show's history and a regular on "Worst Simpsons Episode" lists.
The Al Jean episodes are hated just as much, only for different reasons, namely, being boring, derivative, full of forced humor, and carrying an air of We're Still Relevant, Dammit due to dated pop culture jokes. In fact, it's just safe to say that anything after season eight on The Simpsons is a mixed bag at best, but has some good moments in it, though those have been getting rare since Season 13.
Some fans treat "Mother Simpson" as the only time Mona Simpson appears, as they feel her later appearances cancel out its very powerfulTear Jerker ending.
Pretty much anything after the movie & Uncancellation is usually reviled and often ignored, due to the original producers and writers leaving the series, and the series ultimately becoming a franchise zombie, especially considering that the movie was originally intended to be the series finale.
Some fans tend to excuse season 4 in terms of the uncancelled season discontinuity, saying that while it's not as good as seasons 1-3, it's not as bad as anything from season 5 onward.
And it is most definitely not a good idea to mention the words "A Pal for Gary", which depicts SpongeBob as so mean to Gary and so ignorant and stupid (even by those who tolerated his increased stupidity in later episodes), it's like it's a whole new character entirely.
A good chunk of fans believe that Action (and to a lesser extent World Tour) never happened.
In a reversal of the trope, quite a few Star Trek fans did consider the Star Trek: The Animated Seriescanon when it officially wasn't (except for certain details, verified later in-canon). It was declared canon after a poll on the official Star Trek website in the late noughties, leading to the trope being played straight with fans declaring Discontinuity on that series as well.
Yesteryear was an almost universal exception, beloved for portrayal of Spock's childhood on Vulcan. The backstory the episode established for Spock is considered to be a completely canonical history, and elements of the episode made it into the 2009 franchise reboot.
Even those who acknowledge the last season often ignore the finale episode Phantom Planet, due to its revealing Danny's secret to Valerie and his parents, and possibly the world. They prefer to play around with the plot ideas that were nullified by this episode.
Avatar The Last Airbender episodes "The Great Divide" and "Avatar Day" receive this. Although the latter gets a pass as it fills in history on one of the previous Avatars.
There are more than a few fans who disregard the reveal of Amon's true identity, and his true motivations, preferring the character as he was before said reveal.
Although liked as an episode, JEM fanfic writers ignore the episode "The Day The Music Died". And yes, JEM fanfics do exist.
Kim Possible fanfic writers ignore the hook up between Bonnie and Senor Senor Junior. This may have to do with the fact in the episode where said hook-up happens, Bonnie rigged an election to become homecoming queen (instead of Kim) and we also learn Brick Flagg (her ex-boyfriend) broke up with her. So Bonnie gets Junior as a replacement boyfriend, and gets no punishment for rigging the election. That or it's so they can ship her off with someone else.
Some Transformers fans ignore everything after Transformers: The Movie (the animated one) or Season 2. Beast Wars fans often ignore Beast Machines and/or the Beast Wars-specific comic stories, and others ignore Beast Wars itself. And fans sometimes reject that the comics retconned the origins of Unicron and Primus in every continuity. Many fans also deny The Rebirth as canon, mainly because of it's poor writing, animation, and characters. Ignoring this is made easier by the fact that the anime series Transformers Headmasters takes place after Season Three, but ignores The Rebirth. TFWiki.net has a good article on "Personal Canon".
The 5th season of Teen Titans gets this for introducing a slew of new characters, spending episodes focusing on them, concluding with a Downer Ending finale, and the fact the series was focused on Beast Boy when he had already had a season long arc in season 2.
The trope is also inverted concerning Teen Titans. There are fans who work it into the DC Comics Animated Universe, not caring for any Continuity Snarls.
Shaggy & Scooby-Doo Get A Clue!, which involves the titular characters behaving as though they were secret agents gets this as well on the grounds that the two characters do not behave as they did in prior Scooby Doo incarnations. It probably does not help either that Daphne, Fred and Velma are merely guest characters as opposed to main ones in that show.
Speaking of incarnations of Scooby Doo, in general, the original show has gotten so many adaptations, that many think (especially the older audience) that Scooby-Doo! Mystery Incorporated never happened In-Universe. Still others say that nothing happened after What's New, Scooby-Doo?, others are content only with the classic 70's show.
There are fans of Rugrats who refuse to acknowledge episodes with Dil and Kimi in them as well as the Spin-Off series All Grown Up.
Also considered non-canon is Chad's being a double agent all along during his time with the Teen Ninjasfor reasons similar to Heinrich's twist, to the very final episode where Numbuh One ends up having to leave Earth to help the Galactic KND.
Some 1x5 (or 5 x anyone else) shippers want to ignore the fact that Numbuhs 2 and 5 get married in the future, despite the fact that it had a little bit of foreshadowing.
Several Futurama fans do not count any of the episodes after "The Devil's Hands Are Idle Playthings" as canon and refuse to acknowledge the made-for-DVD movies and the Comedy Central episodes as canon. Then are a few who are more willing to accept the films but feel Into the Wild Green Yonder was the end of the series and none of the episodes after that are canon.
Some fans refuse to acknowledge that Calculon and Roberto are Killed Off for Real (even though there was an episode where Calculon is brought back to life, only to realize that no one wants him back and he ends up dying again after giving the best acting performance of his life).
Most Daria fans hate the episode "Depth Takes a Holiday" so much to the point that fanfics have been written just to explain how it never happened and isn't canon. Granted, despite no All Just a Dream disclaimer at any point, the episode was probably never intended to be taken too seriously or intended to be canon.
The same with "Daria!", the Musical Episode. In both cases it largely has to do with the Bizarro Episode themes interfering with the show's general realism.
It's also best not to talk to any Daria fans about the episodes where Daria dates Tom after Tom breaks up with Jane. Or the episode where Daria has to choose between contacts and glasses ("Through A Lens Darkly"), due to how out-of-character it makes her (despite that, in Real Life, smart girls like Daria can have issues over their appearance. Just because they're not the pretty and popular girls — or even the average ones — doesn't mean they're immune to human feelings and concerns, unless they have severe mental and emotional problems).
Some longtime Xiaolin Showdown refuse to consider the sequel series Xiaolin Chronicles as canon due to network change, more comedic tones, changes to the names of many of the Shen Gon Wu magic items, lack of the original voice cast and production moving to Canada.