[[quoteright:350:[[Series/StarTrekTheNextGeneration http://static.tvtropes.org/pmwiki/pub/images/deja_q_hd_046_resized_6484.jpg]]]]

Let's count the times that we wish that the creators of Star Trek hadn't [[CatchPhrase made it so]] during the many decades that the show has been around.

Keep in mind:
* Sign your entries
* One moment per show to a troper, if multiple entries are signed to the same troper the more recent one will be cut.
* Moments only, no "just everything he said, " "The entire show, " or "This entire season, " entries.
* No contesting entries. This is subjective, the entry is their opinion.
* No natter. As above, anything contesting an entry will be cut, and anything that's just contributing more can be made its own entry.
* Explain ''why'' it's a Dethroning Moment Of Suck.
* No RealLife examples, including Reality Television and ExecutiveMeddling. That is just asking for trouble.
* No ALLCAPS, no '''bold''', and no ''italics'' unless it's the title of a work. We are not yelling the [=DMoSs=] out loud.
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!''Series/StarTrekTheNextGeneration''
* Tropers/JackassOfTheCentury: ''The Big Goodbye''. There were two plots, one involving an interesting test of Captain Picard's ability to establish good diplomatic relations with a race of sentient insects, another involving a rather boring 1940's drama (which is something Sci-Fi watchers clearly do not watch Sci-Fi to see). Guess which plot overshadowed the other? Worse still, they didn't even show a visual of the bugs, not once. Normally, the {{BottleEpisode}}s from the series were the better ones. This, clearly, was an exception.
** Tropers/GrumpyOldMan: This was mine for TNG as well. In addition to the reasons above, it's made even worse by the fact that the 1940's characters were all cliche stereotypes. It comes off as a cookie cutter detective story that pretended to be something interesting.
* Tropers/IraStevenBehrSucks: There's also the end of ''Reunion''. Worf kills a problematic Klingon politician who no one misses, and does so in accordance with Klingon law, creating no actual problems, and arguably solving a few. Picard still reprimands him for this.
* [=InTheGallbladder=]: ''Up the Long Ladder.'' I've seen some pretty bad episodes, but none of them have gotten under my skin as seriously as this one. It starts with a plot that could have seen Pulaski actually demonstrating those positive traits they keep saying she has, then promptly ignores it, but that's not my biggest issue. The A-plot revolves around Star Fleet interacting with the Bringoldis, whose character amounts to no more than "blatant Irish stereotype + blatant Pilgrim sterotype", but that's not my biggest issue. My biggest issue is ...Riker. The writers turned him into human garbage, then pretty much wrote the script around either justifying or validating his godawful behavior. I could point to many examples, but the biggest one is this: When the Mariposans, who reproduce entirely by cloning, ask Riker for a DNA sample so they can save their colony from the impact of nearly 300 years of replicative fading, he turns them down because he feels that cloning him would make him less special. He is considered to be in the right for this, to the point where he faces no retribution for destroying a clone the Mariposans make of him, using a stolen DNA sample.
!''Series/StarTrekDeepSpaceNine''
* Tropers/IraStevenBehrSucks: The part in ''What You Leave Behind'' where they cured the changelings. Sure, it's prefaced as a peace brokering deal, but the changelings had a history of violence and genocide; to trust that this would never happen again is, at best, extremely naive.
* Tropers/{{COFFEENEBULA}}: The last Ferengi episode "Profit and Lace". It's meant to be both funny and serious, and it's neither. I just did not find Quark acting as a female at all, to the point of painfulness. To this day, it's one of the few Deep Space Nine episodes I haven't made it all the way through. Most of the fandom [[FanonDiscontinuity agrees that it's one of the worst episodes of DS9.]]
* Tropers/GrumpyOldMan: ''Valiant''. Other than breaking Nog, there was little point to the story. Throughout the series, Ron D. Moore had found plenty of ways to torment and kill perfectly sympathetic characters, but this was by far the worst example of his writing atrocities. And Nog would later be broken anyway in ''The Siege of AR 558'', nullifying what little purpose this story even had to begin with.
!''Series/StarTrekVoyager''
* @/DragonQuestZ: "Threshold". When you combine all the worst parts of the Franchise/StarTrek franchise (ResetButton, HollywoodScience, TechnoBabble, SpecialEffectsFailure, and CharacterDerailment), can you blame the executives for all but declaring this CanonDiscontinuity? [[WordOfGod Brannon Braga himself]] even admits to screwing the episode up.
** Tropers/{{Tuomas}}: After all the bogus science and general stupidity in ''Threshold'', the final straw, the thing that made this the worst Trek episode I've ever seen, is the last plot twist: the Voyager crew discovers Janeway and Paris, who have devolved into this weird salamander creatures, because that's what traveling at warp 10 does to you... And they also discover the two have mated and have produced offspring! So in the three days they were missing, they've turned into lizards, mated with each other, conceived children, and the kids clearly aren't newborn either, so that's one helluva fast reproduction process. Chakotay then inexplicably leaves the baby salamanders on the alien planet, and they are never ever mentioned again. So the whole twist of Janeway and Paris having kids was absolutely pointless: it doesn't have anything to do with the themes of this episode, and it's completely forgotten by the next one. They just added an utterly silly and unscientific plot twist on top of all the other ridiculous things in ''Threshold'' for no reason at all.
* Halfstep: The 2nd season episode "Alliances." To sum up: Voyager has been getting hit pretty hard by repeated Kazon attacks over the previous few weeks, so Chakotay convinces Janeway to go against her normal Starfleet training and beliefs, and to try to make alliances with some of the Kazon sects that are attacking them. Janeway eventually goes along with this, making contact with several of the factions that have been giving them a hard time. Eventually it is brought up jokingly that they should try to form an alliance with Seska and the Kazon Nistrim. Janeway takes it seriously, much to Chakotay's dismay. Now, there's a bit more to this episode, but the previous is all you really need to know to understand where this [=DMoS=] is coming from. ''Alliances'' is just one long IdiotPlot, filled with people being stupider than normal, making decisions that are questionable even by Voyager standards. A brief list of the questionable stupidity:
## When Chakotay states that they may need to reinterpret Starfleet principles in their situation, Janeway retorts that she hasn't seen any evidence that they've failed the crew yet. Apparently getting stranded in the Delta Quadrant, getting half of two crews killed on what was supposed to be a routine snatch and grab, and having the Kazon smear the Federation's good name all over the quadrant (seen in Dreadnought) while routinely attacking Voyager doesn't count.
## Janeway decides to make the alliance work, then calls in the Kazon Nistrim, the sect least likely to cooperate with Voyager, on the justification that Seska and the Nistrim are as equally bad as every other Kazon sect, when in reality, there is nothing supporting that belief. Furthermore, the other Kazon sects don't have Seska there constantly goading them to take technology from Voyager.
## As part of the alliance, Culluh makes the demand that they do a crew swap. Voyager is leaving the quadrant forever; why would Janeway agree to that, and why would Culluh, mysoginist or no, even think that Janeway would agree to that?
## Janeway meets the Trabe, the species that the Kazon stole their technology from. When the Trabe fleet runs into Voyager, they even talk with her, instead of immediately shooting, even though their fleet has more than enough ships to destroy Voyager (just 2 or 3 Kazon ships have been shown to be enough to seriously cripple Voyager, the Trabe have dozens in their fleet). The Trabe are thankful, polite, and eager to make an alliance with Voyager. So when the Trabe want to execute every single Kazon maj, Janeway has a problem with this because? At worst the Trabe are about as crooked as the Kazon, but they don't have a problem with Voyager. They also didn't seem to have a problem with the rest of the quadrant, as according to Neelix, the Trabe seemed to have a very good reputation. The Kazon are at war with everyone, attack and enslave random races, and won't even deal with Voyager, even though Janeway has bent over backwards to try and deal with them. How is dealing with the Trabe a worse deal than dealing with the Kazon again?
* Troper/Hyrin: ''Unimatrix Zero''. The episode where Janeway gets assimilated ''on purpose'' and the Borg Queen completely loses her shit and starts self-destructing her fleet on a whim. SFDebris's synopsis about this episode is the stuff of legends.
* Tropers/{{Doodler}}: ''Tattoo''. Chakotay's status as the resident MagicalNativeAmerican varied in levels of offensiveness, but this episode was what proved that the writers had no idea what they were doing. To quote, the reason that the Native Americans are magical? They were [[TouchedByVorlons touched by aliens]], who were played by white actors. [[MightyWhitey White]] [[WhiteMansBurden actors]]. Oh, and until they were touched by these white aliens, they were backwards, language-less cavemen. First time I felt the need to take a shower after watching Star Trek.
* Tropers/GrumpyOldMan: ''Course: Oblivion'': The episode combines ShootTheShaggyDog with plot holes and contradictions. Not only were a bunch of innocent beings killed off for no purpose other than to satisfy the writers' sick desires, but there was ''no reason'' that the silver blood aliens should have come to believe they were the original voyager crew to begin with. Silver blood Tom and Kim, at the least, would have had memories, recent memories at that, to contradict this. And why would silver blood Janeway give orders to keep heading for the Alpha Quadrant, repeatedly, even in the face of overwhelming evidence that it meant certain death, ''for her entire crew''? Granted, real Janeway didn't always make the most rational of decisions, but it was never on this level of blatant and flagrant stupidity. And since the silver blood beings are clearly at least as sentient as the Voyager crew they copied themselves from, it can't be explained by biology. While WordOfGod says that this was an attempt at DarkerAndEdgier, that's no excuse, ''even if it's true'', because [[TropesAreTools darker and edgier isn't always better]]. If it were, all non-horror genres would be passe by now.
!''Series/StarTrekEnterprise''
* Tropers/BryceBryans: "Dear Doctor" in which Archer decides not to help a race of dying people because he is led by HollywoodEvolution and believes helping them would violate a directive that hasn't come into existence yet. "Until I have that... ''directive''..."
* Tropers/{{Crazyrabbits}}: "These Are The Voyages" is almost universally reviled by fans (and the cast!), and for good reason: the series (and franchise finale) is a ''Next Generation'' episode in disguise, mixing {{Retcon}}s, out-of-character moments and a genuinely pathetic premise. However, in spite of all that, it might have been possible to excuse it as just being another lame episode... until the speech scene. Captain Archer is asked to give a speech during a ceremony making the founding of the United Federation of Planets, considered to be one of the defining moments in the history of that universe (and something the audience has never seen before). Captain Archer steps up to the podium, opens his mouth to say his first words... and it cuts to Riker and Troi watching the ceremony for a few seconds before terminating the holodeck program and leaving. It could have been one of (if not the) best moments in a series that was ridiculed during its entire existence, but it ends up being a woeful end to the original franchise (as ''Enterprise'' was the last Star Trek series aired in the original universe). Why, Braga, why?
* Tropers/{{Lancel}}: [[GainaxEnding The last sixty seconds]] of the third season finale "Zero Hour." What very nearly redeemed the entire show with easily the best episode of the series to date was instantly destroyed when Enterprise is, without explanation, suddenly and randomly thrown into 1945 Earth. Archer is randomly found by Nazis, and one of those Nazis is an alien. [[http://www.reallifecomics.com/archive/040528.html I am not alone in this]], but this moment tends to be overshadowed by "These Are The Voyages..." (see above). [[http://www.ditl.org DITL]] couldn't give the episode 5-stars because of just how much that ending sucked, and Graham admitted it easily had five stars up until that moment.
* Tropers/RomanatorX: "A Night in Sickbay" is all around complete crap, with rampant JerkAss behavior on Archer's part for no reason, completely messed up morals (why bring a dog on a foreign planet, just to start), and a RomanticPlotTumor between Archer and T'Pol. However, you can actually pinpoint the moment where the franchise crashed into the iceberg. It's as T'Poi is delivering some food to Archer during his night in sickbay. After acting nasty to her, he says this immortal line. "Sorry, I'm a little on edge. I haven't slept very much, but I'm doing the breast I... the best I can." They made a joke about breasts. On the same franchise that's supposed to explain the meeting of humans with other species... and they made a statement about breasts for comedy. At this point, they must have run out of ideas for intellectual comedy and just decided to make a joke about freaking breasts! To seal this as a DMOS, SFDebris called this the moment where the franchise bottomed out, and Website/TheAgonyBooth called it the exact moment where the series pretty much died.
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