Fundamentally, End of Evangelion forms an alternate ending for the series, along with the updated "video & LD versions" of episodes 21 through 24. Fans do exist who would have preferred that NGE ended with its television broadcast of the original ending, some considering the updated ending to be unnecessary retcon that soils interpretation of the show.
...and further ruining things is the game Neon Genesis Evangelions (or NGE 2) for PlayStation 2 and PSP. This was released in two iterations during the Aughts and marketed as containing the answers to the show's most niggling secrets. Much of this material has been translated over the years, and there have been no shortage of appreciative fans — but with that comes a vocal minority crying foul that the game reveals too much and ruins the mystery. (Never mind that with every secret spoiled, many more mysteries have been created.)
If the new Evangelion movies (the fan-branded "Rebuild") end up being connected in-universe to the original Evangelion series, many Eva fans will cry out "RUINED FOREVER" in a singular voice so terrible that it will knock the planet off-axis.
At what point was Armored Trooper VOTOMS Ruined Forever for people looking for a hard sci-fi mecha series? Was it Roots of Ambition where Chirico survived a shot in his heart due to Perfect Survivor status? Was it The Shining Heresy where Chirico was Born Lucky enough to do a crazy ricochet fluke shot into the Order Buckler's cockpit and destroying Teitania's Auxillary Brain, Was it the newer OVAs such as Pailsen Files and Phantom Arc for Sunrise copping out on dodgy computer-generated ATs and it basically amounting to needless padding on Chirico's backstory, Some even claim that VOTOMS wasn't very realistic to begin with when the Quent arc rolled around and The Reveal happened. for bonus points, mention the phrase "Child of God." as that aspect of Chirico's character is a sore spot with many fans.
Then there's - "Sai told Sakura Naruto loves her... WHAT ABOUT HINATA?!?"
The instant revival of everyone who died during the Invasion of Pain Arc pissed off many fans. Of course, the fans were also pissed when everyone died so now they're thought of as unpleasable.
The announcement that Naruto Shippuden would air on Disney XD has obviously not been taken well in certain parts of its fandom. Despite the fact that Viz Media will still be releasing uncut DVDs, so even if it does turn out to be a Macekre there won't be that much reason to complain. As can be seen with Marvel, just being associated with Disney is prone to bring in the ruins.
The dubbing of the show also got this claim after it went in-house, mainly due to the resulting voice actor switch, with the jarring changes made to the voices of characters that fans had become adjusted to. That said, it still fits this trope to a "T". But most of the fans really don't even give a damn anymore, since the new voice actors improved over time (for the most part).
And now for something not related to the voice actors: OMG they changed the "TO BE CONTINUED" text! And the title of the episode was written in English instead of Japanese with English subtitles! So were the credits! The anime is ruined FOREVER!
Some Team Rocket fans claimed the trio was ruined FOREVER!! when Jessie and James were given black uniforms and a serious promotion, along with a new serious-business attitude. In reality, they were made Badass and much more awesome, especially since Team Rocket had stopped being funny years ago.
Several members of the fandom cried 'RUINED FOREVER" after the One Shot character Tobias defeated Ash with a Latios and a Darkrai. In fact, just the very idea of certain Pokemon being used in the Anime has caused fandom uproar.
To expand on that, parts of the online fandom of any given anime tends to say that any anime that gets dubbed into English (no matter how faithfully), is "ruined", despite the fact that no one's ever going to force them to actually listen to the English audio.
Even though the Ghibli dubs are generally respected, there are some so-called "true fans" who insist on hating them simply because they're by Disney, and they object to any change to the dialogue, music, that may have been done to these films, stating that these movies have all been destroyed; an argument which is totally fatuous considering that Miyazaki and Ghibli were both involved with the creation of the dubs. If they don't think their works are ruined, who are such "fans" to say otherwise?
Made even more ironic considering Miyazaki himself stated that for quite a few of his characters he was forced into a form of "Accent Adaptation" due to the lack of any dialect he felt fit the characters within the Japanese Language. A prime example he named is the Witch of the Waste in Howl's Moving Castle.
Speaking of that one: Disney let the younger siblings of Miley Cyrus and the Jonas Brothers voice-act Ponyo and Sousuke (respectively) in the English dub of Ponyo On A Cliff By The Sea? Cue building nerdrage via Periphery Hatedom by proxy.
And on the flipside, with the anime industry scrambling to salvage itself and still turn a profit while still trying to license a diverse bunch of shows, several "niche" shows are being released sub-only. You know, the kinds of shows that put even a large studio like Geneon out of business because the dub cost so much the show didn't turn a profit. Anime is now ruined FOREVER because the industry is "discriminating" against dub fans. Strangely, nobody thinks the industry is ruined FOREVER because of the ongoing recession.
It appears to be very common in mainstream mecha anime. Fans have found something to complain about in every single episode for Code Geass, Macross Frontier, and Gundam 00, with the amount of ruin escalating the higher the episode count is.
Code Geass R2 in particular has the series FOREVER at least once per episode, according to some Fan Dumbs.
Many Fruits Basket fans cried this when it was revealed that Akito is female, which sunk ships everywhere and created a generally hilarious explosion because we all know that Het is Ew and they totally ruined the character for ever and ever.
Fans have different opinions on where this happened in Bleach.
1.) When Hitsugaya (presumably) beat Halibel there was a sudden influx of "Bleach is ta lose!!11one!" When it was revealed that he hadn't even scratched her, very few of those who declared the series ruined came forward to retract their previous assessment.
Particularly sad considering the lack of genre savviness of these viewers; when has trapping an opponent in ice ever worked? (except in Fairy Tail)
2.) Since the start of the Soul Society arc.
3.) Since the END of the Soul Society arc, and into the filler Bount Arc that seemed to go on forever.
4.) Almost any point after the start of Ichigo vs. Ulquiorra.
Many readers following the chapter releases online actually embraced the whole thing and started to enjoy the many inventive ways the author can come up with to "ruin" his manga. The most ridiculous the development, the better! Kubo himself stated that he really loves designing characters and admits to creating new ones as a way to get himself out of writer's block.
Special mention should probably also go to Yammy's Reveal as the 0 Espada, which tended to be viewed as a) wall-bangingly stupid, b) hilarious, c) awesome, or d) some combination of the above.
This has not been stressed enough. Every time something happens in Bleach, it's ruined forever. Starrk didn't kill a billion Captains? He was pointless. Ulquiorra is popular? He's being milked. People expected more of the Vasto Lordes? Kubo overhyped them. The Fake Karakura Town Arc? Too much fighting, not enough character development. The beginning of the Lost Agent Arc? This is so slow it's worse than filler! Kyoraku didn't reveal his Bankai & that's terrible, but the series should have ended anyway. The point here is that the fanbase is unpleasable.
There was also a case of this during the Deicide in which the "fans" had a problem with, wait for it..., the name; complaining endlessly that Tite is an idiot who couldn't spell the word decide right. Said "fans" tended to ignore the possibility that Deicide could possibly be a word itself and didn't even bother to do a simple Google search to do the research. Like the above example very few retracted their statements. It pains this troper how little common sense and basic dignity is left in the Bleach Fandom nowadays, though granted, of cource, that these are only the vocal minority.
Some people say that L's death did this to Death Note, and that Light's death at the end of the series ruined it even more.
Some sections of the Umineko No Naku Koro Ni fanbase tend to think every new and irritating bit in The Anime of the Game (which there is admittedly quite a lot of) has Ruined the series FOREVER. Particularly cutting out all the real-world parts of EP4 after George and Jessica kill each other to give more time to the Meta-World sequences and backstory for a somewhat Creator's Pet-ified Ange.
A second season for the anime Black Butler was announced... featuring an original new protagonist and Butler not from the previous season or manga, and not Ciel and Sebastian. Cue the wailing of thousands of yaoi fangirls around the internet. Which, as it later turned out, was A-1 Pictures just trolling the fandom.
One Piece started getting these accusations once Portgas D. Ace bit the dust, breaking the tradition of not killing named characters, except in flashbacks, that was maintained for 13 years of publication.
Named characters have died, there had just been too many Disney Deaths.
And then, after there was confirmation of a Time Skip happening, it started rising again.
Some people complained about Hancock falling in love with Luffy because it would ruin the series being strictly No Hugging, No Kissing. Thankfully, this was averted.
Parodied in Darker Than Black with Kiko and her otaku friend. After months of giddy anticipation over the next release of their favorite anime, they storm out in anger over how it's Ruined FOREVER, and Kiko will not let the director get away with this!
Heck, the entire idea of Marvel Anime (having popular Marvel superheroes in anime style made by Madhouse) may be seen as RUINED FOREVER by many anime and Marvel fans alike, mainly because having popular American superheroes in Japanese anime style is seen not to fit well with each other. Of course, the reception of the Marvel anime idea received mixed reviews from fans and critics alike.
The episode in question was about 90% sexual fanservice and isn't even canon.
Many people complain over the Viz re-releases of Pokémon Special for various reasons, the most legitimate complaint being that there seem to be no plans to release the third gen story arcs until/unless the Ruby/Sapphire remakes come out, leaving out about 15 volumes worth of material out that will inevitably cause massive plot holes and spoilers in the currently on-going Diamond/Pearl arc.
The Ruby/Sapphire chapter is finally released, but the above still applies as it'll never catch up to prevent the spoilers.
It doesn't matter how many years have passed, several fans of Dragon Ball feel the series lost it with the switch to Dragon Ball Z and the more sci-fi and less comedic emphasis, even though in the latter's case the humor was already being toned down a little by the time Piccolo first showed up.
Don't even mention Dragon Ball GT to Fan Dumb. They will instantly bring up the idea that GT was not canon since Akira Toriyama did not involve in the development. Their reasons being Goku became a One-Man Army and Marty Stu, and other major characters in the previous series existed to be kidnapped, brainwashed, turned into punching bags, or even killed off.
The Buu Saga is this for many fans with its overall change in tone from dark storylines to focus more on humor and, to the hardcore Gohan fans, its treatment of him from the main character to supporting role.
Don't ask Medabots fans what they think of Spirits (The second series), there's better ways of committing Suicide by Cop
Apparently Season 2 of The Mysterious Cities of Gold is ruined forever, because heaven forbid, they used CGI to animate it, instead of animating it in the exact same manner that they did 30 years ago. Never mind the fact that they managed to find the majority of the original voice actors from the original, and that the original story was so good that they are able to do a "season 2" with the original premise, 30 years later, as opposed to having to do a complete reboot to explain away old shame, bad writing, stupid episodes, people not doing the research earlier (you know, like ThunderCats, Voltron, He-Man, TMNT, and every other 80's cartoon revival since then have had to in order to have any semblance of viewability today). Never mind that they were able to keep the same musical atmosphere of the show, except for updating the instruments and cleaning up the background. It also sucks that everyone looks almost virtually like they did in 1982, except for those pesky faint hatch marks and edges that you could see if you looked hard enough: how dare Blue Spirit Animation even think about cleaning up the animation, adding camera shots that have been in use for animation for 20 years, and generally standardizing the drawing across the board!!! Anyone want to bet that MCoG would still be ruined for these people if the creators recast everyone, did a bunch of race lifts, changed the theme song, and generally updated it like so many "fans" seem to be demanding?
Quite a few fans called this when Sword Art Online moved onto the ALFheim arc. First off, it killed off what would've been a great (and emotional) conclusion to the series. Then, Asuna became a Damsel in Distress and Adaptation Distillation removed any evidence that Liz, Silica, Agil and Klein were also in the game. They're instead pushed aside for Sugu and her feelings for her "brother" Kazuto/Kirito. When Episode 21 hit, the arrival of Tentacle Rope had the fanbase screaming and Episode 24's Attempted Rape of Asuna in front of Kirito sent most who had stuck with the show until that point nuclear.