There are subjectives, and then there are these. While you may believe a work fits here, and you might be right, people tend to have rather vocal, differing opinions about this subject. Please keep these off of the work's page.
No ALLCAPS, no bold, and no italics unless it's the title of a work. We are not yelling the DMoSs out loud.
King Clark: While I was reading throughout the NGE Fanfic Recs, I came across one title that sounded interesting: Arsenal. It starts off as a Peggy Sue fic, but quickly turns into a rollercoaster of insanity. Throughout the story, Shinji goes around doing ridiculously awesome, yet unquestionally corrupt things as a Necessarily EvilSociopathic Hero, all in the name of preventing the Third Impact. Shinji starts the story off by doing things that are worse than what Gendo did for most of the series, but nothing too evil. There are signs that the story might be shaky in the way that Shinji causes his new underlings to change their ways quickly, but it isn't anything that isn't unforgivable. Unfortunately, the conclusion of the Black Bunnies arc takes Shinji beyond the Moral Event Horizon and completely ruins the viewer's ability to like the protagonist in one fell swoop. The three Black Bunnies are all established as extremely immoral and evil, and Shinji decides how he'll deal with them: he plans to use nanomachines to destroy their nervous systems entirely, in order to place them each into a Fate Worse than Death that is borderline And I Must Scream material. No one has any objections against his decision beforehand (not even Misato, who even helps set up what Shinji has planned for them). As for the punishments themselves, they are as follows (spoilertagged for high amounts of Squick): Kaede, the first Bunny, is subject to 48 hours of Cold-Blooded Torture, and is then forced to become a bodyguard who is coerced into pain if she so much as thinks about her past. This is easily the least harsh of the punishments. Satsuki, the second Bunny, has her brain permanently damaged and reduced to acting as what can best be described as a human dog. To add insult to injury, Shinji decides to give her a collar, make her sleep in a basket and eat out of a bowl, while the only desires that run through her mind are to recieve affection from her "master". He decides then to keep her as a sex slave for no other reason that she would have done the same to him, but mainly because he fucking can. It gets worse, though: Aoi, the third Bunny, has her abilities to smell, taste and touch numbed forever, and is left tied up in shackles in a chamber. The population of Tokyo-3 then covers her with graffitti (this isn't even Refuge in Audacity anymore; it's just grotesque and utterly ridiculous). Finally, a man decides to use her as a toilet, all while she can only beg for death. Shinji then gloats about what he's done to his father, and tells him what he's done all while sounding extremely pleased. Afterward, Gendo is visibly disgusted with his son's treatment of the Black Bunnies in spite of the fact that he approved of the use of these nanomachines in the first place. So, does Shinji have a shred of guilt for what he's done? Absolutely not. The only thing that comes close to that is his remembrance of what Asuka said to him in the canon, but that hardly counts. Remember when I said that Shinji's actions were all in the name of stopping the Third Impact? This has absolutely nothing to do with it, so the author just turned an interesting character into a sick freak without a good reason. What's even worse is that the author has claimed that he considers these things to be proportionate punishments to them. No one, not even the worst of villains, should experience fates as disturbing as these. The protagonist has practically become a prime example of a Designated Hero with this action, and has been warped beyond recognition from his canonical counterpart. I'm too disgusted with this story to read through it any further, and I'd rather not see whatever the author turns Asuka into (assuming he's still churning out this filth). It's a shame that They Wasted a Perfectly Good Plot, too; from the premise and some pieces of the plot, this story is a prime example of What Could Have Been a good, interesting read. note Phew. That sure took a while, didn't it?
Jonn: Harry Potter And The Invincible Technomage. I stopped reading when Iron Man comes storming into Hogwarts, during breakfast, and gets angry at Dumbledore for putting his son in danger. The person who put Harry in danger was Harry himself. And Dumbledore's response: does he explain the situation? Does he try to take it someplace more private? Does he act like a harmless eccentric? No, he promptly tries to mind control Iron Man. This is so out of character I literally cannot imagine canonical Dumbledore doing it.
Time Traveler Jessica: For me that actually came later, but with the same character. I was willing to accept that this fic was going to use a darker interpretation of Dumbledore, because frankly I think it's a legitimate Alternative Character Interpretation. But at one point Harry and Tony's work on combining magic with technology has led to Muggle music being played on devices in Hogwarts, and Dumbledore is against it. Whatever else you can say about Dumbledore, he is the only character in the books who had anything to do with muggle culture - reading muggle newspapers and liking muggle candies - so I refuse to believe his reaction to this new source of interaction with muggle culture - which even the Slytherins were getting into - would be anything short of delighted.
Mokyn- A How to Train Your Dragon fan fic, Principles and Elements, was one I was actually very much enjoying the first time I read it. It's an AU of the movie that also fits in supernatural elements of witches and vampires to add to the dragons, and while by no means perfect, It was perfectly good in my eyes. Until about chapter 14 or so (my memory is foggy on this). During a big battle between many of these supernatural factions, there is a sentence that says "Bodies fell to the ground like prisoners in a concentration camp." Buh... What?! I'm reading a fun adventure with dragons and witches and things, and the author suddenly decides to pull out Holocaust references?! I had only recently watched Night and Fog at the time, a documentary showing just how gruesome the concentration camps were, so I I immediately got the images of that in my head and back-buttoned out of the fic right then and have yet to return to it. The most annoying thing? They could just written, "Bodies fell to the ground" and the story would not be affected. They used a horrible, horrible moment of human history for a throwaway sentence! This still bothers me even after months of leaving the fic behind.
The Dog Sage: Not to mention that the author is wrong. It didn't happen for "no damn reason". It happened because Ash decided to help an enemy who's attempted to kill him and those he cares about on several occasions. His "explanation" is just a cop-out, something that authors use whenever they want to try and justify a Shocking Swerve. And having the character holding the Idiot Ballhang a lampshade on it just makes it worse.
On Soaring Wings For the most part I tried to enjoy The Laughing Fox, even though I thought the author was kinda a jerkass (Making a poll for whether he should spare Zabuza, and Haku then telling everyone it didn't matter what they picked, he was still killing them off.) But then there comes a massive Moral Event Horizon that makes the entire series completely unreadable when Batman, John Stewart, Nightwing, and Martian Manhunter are captured by Konoha ninjas where Joker is currently living. The heroes are then brutally tortured, muliated, and psychologically broken in the worst ways I could possibly imagine. At no point whatsoever does anyone ever question the morality of this action, not even The Third Hokage! Designated Hero does not even begin to describe it.
St0rmrage14: Not to mention the very idea that Batman, John Stewart, Nightwing or Martian Manhunter can be broken by torture. Those four men are some of the biggest determinators in the entire DCU! John Stewart's powers actually run on his will power! And the man practically recreated an entire planet with just that! J'onn near literally watched his entire species die out in an inferno and didn't break. Nightwing helped defeat Trigon! And Batman has recovered having his damn back broken!
Super Saiya Man: From the well known and beloved fanfic, A Mothers Love by Lord in the Land of Fire. Okay, I can forgive Four-Tailed Naruto taking down a noob MS Sasuke (even though it was an Infuriating Anti-Climax), I can forgive Orochimaru going down so easily. I can forgive Gaara's death. What I can't forgive? Naruto fodderizing all of the Akatsuki, including his counters Pain and Kisame, the second he regains the Fox and controls it. Seriously, LILOF could have made an epic, several chapter spanning arc of a Hokage Naruto who just mastered the Fox taking on Akatsuki if he wanted to do it alone. Instead... he fodderizes them in one chapter. Nevermind actually justifying the Uchiha Massacre in this universe when they became Properly Paranoid about Naruto's intentions to their clan after several biased posts. In canon, its rather ambiguous. Here? Konoha deserved that rebellion...but instead Konoha goes on and conquers all nations, Naruto gets a second wife, and starts a Pax Romana. How much more God-Mode Sue can you get?
Super Chaos: I've never liked Pokemon Revolution by Farla (mainly because she takes the animal rights thing too far) and Charles Rocketboy, but the absolute low point is chapter 17, when Ash and Gary suddenly become even more out of character than they already were. Random juvenile insults (dickhead, etc.) are thrown as Ash and Gary are fighting for no real reason. WTF.
Gun Psycho: Past Sins, despite being well-written, is pretty bland but tolerable for the most part thus far (Not so much just reading it but commentating on it as well to be honest) until chapter 10. The absolute nadir for me was the part where Queen Nyxie trying to bring about eternal night just because it was what was expected of her. (to be fair, she was abandoned, but a might extreme a reaction don't you think?) I pretty much stopped caring after that part. However, since I started "reading" the story, that doesn't mean I'm turning back now.
45xxx: I have my own moment from Past Sins. Namely, Spell Nexus brainwashing Twilight in chapter 16. Why? ... let me explain it to you like this: I really find it a little wrong to brainwash a mother to tell their child to their face how much they don't like said child. It doesn't help any when said mother attacks their child, and the brainwasher in question uses this as an excuse to hang said mother. I've only read chapter 16 all the way through once, and, since then, I skip that large part. If it wasn't for Nyx saving Twilight from being hanged near the end, I would've skipped the chapter entirely.
Some New Guy: The Reset Button in Nobody Dies, mainly because it completely negates all the excellent Character Development of season 4. Ichi is back to being a near-catatonic wreck. Uri is back to being an overprotective, arrogant asshole. Mana is still a slave in all but name to NHIS. Gendo still hates Ichi for something that wasn't even her fault. All because the author wanted to appease the Vocal Minority that disliked season 4.
kablammin45: This otherwise cool fanfic about Ed, Edd n Eddy in Kingdom Hearts has the chapter in the link, which midway through, the world of Johnny Test blown up. Call it a Crowning Moment Of Awesome, but for this troper, who is pretty much neutral to that series, with the lack of angst from the good guys, as well as some mean spirited mockery at some poor dude who wanted Johnny in it, for this troper it kinda crossed the line btween CMOA to Dude, Not Funny!. (Of course YMMV)
A Black Raptor: For me, a relatively good story called Spider-Man: Partners reached its DMOS in chapter 50 when the author quit caring about grammar. Nobody in the story since has been able to convey realistic dialog. At times it seems just a little out of character, but Between Chapter 50 to 53 (possibly moreso, since as of this writing chapter 54 only just came out and I'm yet to read it, but 53 seemed to improve) the dialog has became so bad that it looks like a child has written it.
Goldude: I enjoy The Vinyl Scratch Tapes, and I'd really like to continue enjoying it. However, there's something that's stopping me. In the latest chapter, Luna visited Blueblood's and Trixie's radio show. After some talking, Luna tells the both of them that their justice was misplaced. Then Vinyl Scratch shows up, prompting Luna to Kick the Dog by convincing Vinyl that she's a horrible person. This is horrendous for a number of reasons. First, there's the fact that Celestia was completely fine with Vinyl calling her out like that. Celestia never got angry, she never even got irritated. If what Luna said about there being no other choice about Celestia banishing Luna to the moon, then why didn't Celestia not have any problem at all with Vinyl Scratch calling her out? Secondly, Luna had just gotten finished teaching both Blueblood and Trixie a lesson about getting justice when there's no need to. Since Celestia had absolutely no problem at all with being called out, this makes Luna the one trying to achieve justice when there's no need for it. So not only is Luna a complete jerk, she's also a hypocrite. Third, there's the matter of making the banishing Luna to the Moon being no other choice canon. There's no signs of this being true in any of the earlier chapters, so this just comes completely out of left-field. This also makes the fact that this development either makes Celestia stupid for not telling Vinyl that there was no choice, or Luna is completely misinformed, making her a complete jerk, a hypocrite, and stupid.
45xxx: Buddy, you hit the nail on the head. That chapter I hate for the exact bit you described. In fact, I still hate it in spite of the Author's Saving Throw done in the next chapter. (Brief aside: I don't think Luna was legitimately sorry for what she did. This pisses me off even more.)
Falcon Pain: On the subject of Sailor Nothing, there are a number of things I find it hard to stand in a work. Two of them are Author Tracts that go against my principles and characters behaving illogically in order to make the plot happen. So I had a real problem with the movie theater scene, a scene that is largely irrelevant to the plot in which a working adult refuses to sell his product to an interested consumer simply because she is unpopular at his child's school, leading to a speech in favor of illegal downloading.
xployalist: A fairly engaging retelling of Majora's Mask,"Looking back at Termina", was highly enjoyable up until chapter 6. This troper's enjoyment of this fic completely nosedived at two sentences. "Malon took out a sandwich and tossed it to Link. Link looked inside and found a Deku Scrub sandwich. It warmed Link's heart to know that Malon still went all out to find his favorite meats." Up until this point, I regarded this fic as an above-average retelling with a framing device. But because of this trio of sentences, this fic was rendered irredemable. First of all, Deku Scrubs are shown by their character design to be plant people, and therefore not have what we would recognize as "meat". This is also shown by Deku Link's vulnerability to fire: wood burns much more easily than flesh. Secondly, Link is willingly eating the "meat" of a sentient being that someone murdered, and no one has a problem with it. He undoubtedly knows that Deku Scrubs as sentient lifeforms, as they are shown to be capable of speech and barter in Ocarina of Time and have their own friggin palace in Majora's Mask, complete with architecture, organized security force, and music. Thirdly, Deku Scrubs aren't like cows. Sentient beings usually don't enjoy being killed to serve as the consumable energy source of others, and will voice their complaints towards you. They're smart enough to try to escape being cattle that will eventually die to feed others. So where is the "meat" coming from? Did Malon go out to the Lost Woods and find a Deku Scrub to murder and slice into pieces, all for Link?
REV 6 Pilot again, this time for An Experiment. For at least the first twenty chapters, this is an interesting sort of crossover between My Little Pony: Friendship Is Magic and Portal, full of the wackiness that one could expect from a fusion of those two fandoms. Then Twilight starts to fall for Wheatley, and that's when things go to shit. For some reason, the amiable unicorn we all know and love undergoes a considerable lot of Character Derailment, becoming the typical abusive anime girl with the Double Standard: Abuse, Female on Male to back it up. Just because Wheatley is Oblivious to Love and says she is his best friend when she gives him his custom suit, she blasts him with magic. He takes the wrong hint and asks if she's in heat. She responds with a hoof to his face. When he makes the same off-hand comment to Applejack later, she throws a freaking table at him! Seriously, Midi, what the fuck? Is that supposed to be funny? Sure, the latter two were somewhat rude on his part, but that does not warrant violence of that degree, much less so coming from the member of a race that is depicted in canon as not nearly as violent as you made her out to be!
fluffything: Years ago I stumbled across a Danny Phantom / Winx Club crossover fanfic (I cannot remember the name of said fanfic, though). The fanfic in-and-of-itself was your typical mediocre written-by-a-teenager crossover you'd expect to find on the internet. The DMOS comes in when one scene has Dan Phantom (AKA Dark Danny) raping one of the Winx Club members (I think it was Bloom). Just..No, no, no. There is so much wrong with that I don't know where to begin. For one thing, Dan doesn't rape people. Yes, he is a psychotic evil monstrosity that enjoys murder, destruction, and being a total ass in general. But, he is certainly not a rapist. Second, really? Just, really? Look, rape is a very serious issue and should be handled delicately and with a respectful tone towards actual rape victims. This crossover fails to do so. It's nothing more than your typical Rape as Drama teenybopper scene. Disgusting doesn't even begin to cover it.
Dialga X: Cornova's latest story Poké Wars: The Convalescence was pretty good but hit a major low point with the conversation between Ash and Misty when he goes to have his hair cut.
"Is the length okay?" Ash studied himself in the mirror once more. "The length's fine." "How about the style?" "The style's fine, just make it a little cooler." Misty rolled her eyes and sighed, repositioning her hands to her hips. "Just telling me 'cooler' isn't helpful. Give me something to work with. How much is a little?" "It needs to be like fifteen or twenty percent cooler?" Ash offered sheepishly. "You're impossible sometimes," the red head grunted.
The "twenty percent cooler" line was a gratuitous MLP:FiM reference that was shoehorned in just so Cornova could show that he's a brony.
nicktoonhero: Ask Pun Pony is a rather amusing Ask A Pony blog about an Original Character pony who goes around making (often) bad puns. But this one particular entry is what practically ruined Pun Pony in the eyes of nearly all of her followers. Pun Pony becomes an Author Avatar for the writer who was drawing her at the time, and she starts giving out her incredibly negative views on the Mane Six. All the stuff she says about them are completely off, having such gems as calling Rainbow Dash a living stereotype about pegasi, and calling out Twilight Sparkle for treating the very library she lives in like her own personal home. And apparently, she doesn't have anything bad to say about Pinkie Pie, even though she has flaws of her own. This entry is basically the equivalent of the times Brian talked about his beliefs, which are known to be very pretentious. Overall, the entry is not funny, it has little to do about a pony making puns, and it angered a lot of bronies (including me) who know the main characters like the palm of their hands.
Some New Guy: Mare Do Well Meets Her Match has the Humiliation Conga The Mane Five (sans Rainbow Dash) after protagonist Rob Stallion dies in a Heroic Sacrifice against a Hydra the Five had unknowingly awoken during their Mare Do Well plan. Yes, Twilight and co screwed up, majorly, but the way everyone calls them out for what they've done just seems way over the top and dark. Thankfully, the following chapters after this event are much better, but this was the low point of the story in my opinion.
GranObs: RainbowDoubleDash's Lunaverse winds up here with the season 1 conclusion, At the Grand Galloping Gala. A huge Mood Whiplash from the previous stories, this fic shows the government of Equestria as grim, decayed, and fundamentally corrupted to the point where there is literally not one good legislator or noble in the nation. The first six chapters of the story are Trixie trying, and failing, to get funding to rebuild the wrecked town of Ponyville. After Luna finally gets them the money, Trixie and co. realize the only way to stop the corruption in the Court is to literally have a blackmailer arrested by the Guards so she'll tell all she knows in exchange for a plea. This done, Luna flips out at the Court, castigating them for being terrible and says that all of them are hopelessly corrupt. (Trixie, who has done more bad things than many ponies on the Court, is excluded, because she's the protagonist and it's okay when she does bad things). She threatens to disband the government if even a single Courtier steps out of line again, which is ridiculous considering the country is about to be invaded and unfair to boot. The L6 then convince Luna that it's okay to rule by fear. The story ends with Trixie pretending to poison Blueblood and ordering him not to tell anypony about what she did or else she'll trigger the poison, an action absolutely identical to the ones Luna just castigated... but again, Trixie is the protagonist, so it's okay.
Knight9910: I'd like to complain about a fanfic I was actually a part of (though I wasn't one of the writers at the time). Super Smash Stadium, the REX storyline. This was intended to be an "interactive story" linking the forums and the site, with a villain named Rex (or !REX Airship! as he was known on the forums) appearing, messing with people on the forums, and then being defeated in the fic itself. Sounds fun, right? It might have been... except that the guy they got to play Rex ended up being one of the writers' sadistic hacker friend and he... went pretty crazy. Rather than the light-hearted messing with fans he was supposed to do, he actively tormented people, made them believe the site itself had been hacked and was now going to be gone forever (this coming just a few short months after the message boards actually were hacked didn't help), threatened members with computer viruses, and generally made a huge mess of things. Many members left out of fear, and many more left in disgust when Rex's true identity was revealed. Definitely, definitely the lowest point for the Stadium.
MF1993: I will admit that I only watched thecrossover part of Double Rainboom. By itself, the idea of bringing in The Powerpuff Girls is a massive Headscratcher for a fan video that was supposed to emulate the style of the show it's based on, but what made shook my head is how they portrayed them. Needless to say they really Took a Level in Jerkass in this fic. When the monster just gave up and left, the girls chased after the monster to finish him off, despite the monster begging for mercy instead of just letting him go like Rainbow Dash did. My reaction was pretty much identical to Rainbow Dash. As a guy who watched The Powerpuff Girls growing up, I know by heart that they would never do that. While they can get violent at times, they are also very merciful and I don't remember them just normally beating up bad guys when they are begging for mercy, or at least when Craig McCracken was still working on the show. I also thought that Blossom seemed much more irresponsible then she was supposed to be. The way she said to give Rainbow a head start with an evil smirk is once again out of character. I thought they would try to help Rainbow out after playing with her for awhile, but they just chase her around town without a second thought. Overall, if you are gonna make a crossover, go ahead, but please make sure to get the characters right before putting it in the video, especially if you want to give it to an audience who has never seen the crossed franchises before. You really need to give them a good impression. This does not give them a good impression is all I'm saying.
Some New Guy: The Coop, following weeks of inactivity, provides us all with a needlessly bleak, super-"edgy'' sudden downer ending apropos of absolutely nothing—every Scootaloo other than Factory dies a horrible, graphic death, all just so the author could make a reboot. If that ain't a horrid note to end/start on, I don't know what is. Not since the constant Diaboli Ex Machina of Motherly Scootaloo has a pony tumblr pissed me off this much.
Falconwing: Now I loved Shinobi Of The High Seas. I think it's one of the best fanfics of it's genre on the sight. However one moment that really irritates me in hindsight was the fact that Naruto wasn't even at the Battle of Marineford. Now look I don't like it when crossover characters hijack the plot entirely, however there is only so much In Spite of a Nail I can take. This is literally the fourth time, Naruto's presence has had no real impact on the story or the events of canon. Taking things to the other extreme is no less annoying than having him around to change anything. If his prescece in this world has no real impact on the Straw Hats' journey, then why the hell is he even interacting with them at all?
Calamity2007: Don't get me wrong, I love Diamond In The Rough but episode 13 has a moment which bugs me. It is the scene near the end of the fight between the Diamondback Beasts and Flandre, where they decide to "Screw Spell Card Rules" and paralyze her. Now the problem I have is that this seems to ignore Flandre's natural ability to destroy anything at will, which is why she is always fought with Spell Card Rules, to suppress this ability. It just seemed that Spaztique conveniently forgot that she could do that just for a Wham Episode. This becomes especially annoying when you see the previous episode where Tenshi, takes on a not so subtle rant about misinterpreting the characters, like Yuuka being a sadist or Tenshi being masochist. Then come the next episode and it seemed that Spaztique ignores Flandre's canon power for the sake of drama. The next episode attempts to Hand Wave this by Flandre believing in Honor Before Reason but that still is a fan-created personality trait, and thus can be taken as a misinterpretation, just to excuse this scene and center the blame on Brolli.
TheDogSage: From the Kenchi618 fanfic "Better Left Unsaid", we have a scene in chapter 6 where Kurenai catches Naruto smoking. Now, Kurenai is not his caretaker in this fic, nor has she had anything to do with him before this. Now, when she catches him, she decides he needs to be punished, despite, as said before, she's not only not his caretaker, but this is her first meeting with him. And how does she punish him? By stealing his and his team's money to buy him three cartons of cigarettes, which equal 48 packs according to this fic, and forces him to smoke them. All at once. Now, considering a pack has between 20 to 25 cigarettes in them, this means that she forced Naruto to smoke between 960 and 1200 cigarettes in a single sitting. By all rights, he should be dead'. And noone says or does anything about this horrific act, and she's allowed to get away with essentially torturing him. The fic even states he puked and lost consciousness afterwards. And it doesn't even work. All she does is get him addicted to cigarettes.
Korodzik: The My Little Pony fanfic Of Challenges and Kisses begins as an adorable, humorous and very promising story about Featherweight's awkward school crush. Then, however, the author apparently decided this wasn't interesting enough and proceeded to insert raunchy jokes about sex toys and genitals... culminating in the Dethroning Moment where, out of the blue, Twilight Sparkle and Cherilee have almost on-screen lesbian sex while Featherweight is watching. How in the world could anyone think it a good idea to turn a perfectly good, cute story into a crass sex comedy without warning?