If you could remove any episode(s) from the ST canon which would they be? TNG: Code of Honour This was bad even by early TNG status. VOY: Threshold Hasn't even the writer of this episode almost disowned this episode? ENT: These Are The Voyages It's hardly what a would describe as a valentine to the fans, the preceeding episodes gave us a much better finalé, and we didn't get to hear Archers speech (though if it was about Gazelles that might not be a bad thing ) or the signing or the Federation Charter.
I would keep Code of Honor (which I like) and instead de-canonize Masks, what a piece of crap. Yes yes, they were trying to be artsy, still think icky.
Probably 'Force of Nature' if warp was really bad for space the galaxy would have been destroyed along time ago, there have been civilizations with warp technology for hundreds of thousands of years, you had the T'kon, and those humanoids that seeded the galaxy with their DNA. Also don't large celestial bodies bend or in other words warp space-time all the freaking time naturally?
I can imagine decanonising an episode for two different reasons: 1) I really hate that episode, or 2) That episode gives all kinds of continuity /logical problems and contradictions, even so severe that the only 'reasonable' course of action would be to just ignore the episode altogether. For example, I might pick threshold because of reason (2), but I still do not hate that episode. When I watch it and try not to think about it, I find it actually a kind of fun episode. Fury, on the other hand, doesn't have too many continuity problems that I can think of right now, but I might 'decanonise' because I really hate it. Though I'm not even really a Kes fan, I didn't like the way she was used there at all.
Off the top of my head, TNG's "True Q" (has Riker and somewhat Picard, Crusher and Q acting out of character, makes the Q Continuum seem too humanlike and somewhat gets in the way of "Q-Less" and "Tapestry" working as direct sequels to "Qpid").
For TOS, probably either "The Alternative Factor" or something from the third season. For TNG, I'd probably get rid of "I, Borg." I've always hated that episode, as I thought it was absurd that they were even having a debate about eliminating a race that until then had been painted as Space Nazis Cubed. I'm sure that DS9 had some horrible episodes that I'm forgetting, but I'm drawing a blank right now. For VOY, I'd really prefer to just get rid of the entire show, so I'll decanonize the pilot. On ENT, yeah, the last episode was pretty damn bad, so I'll choose that one so the show could end on a high note. And Into Darkness is toast.
I would get rid of the ones where they discover something that should be game changing but is forgotten about. Enterprise Incident, the Feds get cloaking. And never use it. Plato's Stepchildren they discover a chemical that gives you telekinesis. Threshold, you can be everywhere at once and magically de-lizardized by a holographic doc. They shoulda been home tomorrow. Nope.
TNG: Nemesis Not an episode technically but erasing Data's death would be the best thing you could do to TNG. DS9: Forget the name of the episode The one where Bashir is revealed to be genetically enhanced. Totally ruined his character and contradicted previously established development, while also trivializing all his best accomplishments. Voyager: Q and the Grey Not the worst episode of Voyager, but the one that did the dumbest thing with something awesome.
"Turnabout Intruder" just so we can stop arguing about whether there were female Starfleet captains in the 23rd Century. And, frankly, TOS deserved to go out on a higher note.
ENT "These Are The Voyages" doesn't count because it was Riker's holodeck fantasy of something that may have happened two hundred years ago. It couldn't possibly be accurate. TOS "Spock's Brain" and "Turnabout Intruder" get my vote. And VOY "Threshold"
Probably all of TNG. It made the Trek universe a much less colourful place. And elevated technobabble from background chatter to the cause of, and solution to, all of life's problems.
On board with both of these. Spock's Brain introduces The Teacher---why would't they go back for it or to study it? Turnabout Intruder is just such garbage. Gah. Extreme Measures in DS9. They were waaaay too quick to kill off Sloan (William Sadler), and it's a fairly weak episode in my opinion, too, because I thought Sloan, for a master spy/Section 31 operative, was far too easily captured.