Favorite Time Travel Episodes?

DS9 Trials and Tribble-ations

it's not an "episode" but Star Trek IV: The Voyage Home

TNG Yesterday's Enterprise I've also always found to be an intriguing glimpse at an era we've never really seen otherwise

It's hard to choose a favorite, but one that comes to mind is the Star Trek Enterprise episode "Carbon Creek" where some Vulcans crash land on Earth in the 1950's (before first contact) and introduce humanity to velcro.

+1 for Carbon Creek. I guess it's technically not exactly a time-travel episode, but it scratches that itch better than most.

My far-and-away favorite though is Paste Tense from DS9. The conversation between Bashir and Sisko in the tent city hits me like a hammer on the heart every time.
Loved that one. I cry at the end.

Does Voyager's Shattered count? The ship being split into different phases in time both past and future. It's one of my favorites.

For DS9 - Little Green Men and Trials and Tribble-ations are classic!

I'd say Shattered counts since it's in: https://en.wikipedia.org/wiki/Category:Star_Trek_time_travel_episodes

Chakotay needing to convince past Janeway to trust him and follow him through various events of past episodes was pretty interesting.

The DS9 episodes were just fun and I feel like there's not many that go back to that time period like Little Green Men did. Most time travel episodes either go further back (1800's, WW2 itself, etc) or are set in the 'present day' (Voyager's/Enterprise's/Picard's).

My far-and-away favorite is Paste Tense from DS9. The conversation between Bashir and Sisko in the tent city hits me like a hammer on the heart every time.

Least-favorite would have to be the lion's share of Picard s2, but specifically the episode where the gang tries to pull an Ocean's 11 at that gala event and Picard gets run over by a car.

What's funny is that I really loved Picard S2, the gala thingy included
Past Tense is such a well done two-parter, too. Having watched it again recently it’s a bit scary how close it came to reality…
Least-favorite would have to be the lion’s share of Picard s2, but specifically the episode where the gang tries to pull an Ocean’s 11 at that gala event and Picard gets run over by a car.

I agree. And that episode was especially stupid, but it was a special kind of stupid. I thought the late Annie Wersching's performance as the Borg Queen was a highlight. It reminded me of Wayne Pygam's scene-chewing-but-snarky performance as Head Scorpius from Farscape. And then Alison Pill got to show off her pipes singing "Shadows of the Night" while the band and spotlight operator jumped right in. Made no goddamn sense, but I loved it.

Also, Pat Benatar is now canon in Star Trek.
- Made no goddamn sense, but I loved it.
  
  Ha. I just assumed she assimilated an ipod somewhere between scenes.

TNG: Time's arrow. I loved the Guinan backstory, Mark Twain, the western setting, and especially that it was all Data centric.

TNG's All Good Things is probably my all-time-favorite; with close-seconds to DS9's The Visitor and TOS's City on the Edge of Forever as runners up. Honorable mention to DS9's Far Beyond the Stars, while technically a vision/fever-dream it's one of Star Trek's finest hours.

Far Beyond the Stars is probably DS9's best episode IMO - but it's funny, I never considered it a time-travel ep before. I guess it fits that bill too.
- I suppose it sort of is a time travel episode?
  
  Avery Brooks’ acting in that one is top notch either way.
  
  I also suppose if we are counting it, then we should also discuss The Visitor. Tony Todd does such a great job as old Jake, and as a father myself, this episode hits the feels really hard. And then later Tony Todd is back as Kurn and there’s no way you could tell it’s the same actor, other than his voice.
- Yeah, it never occurred to me to count it but if it counts then it has to take the crown.

There are so many good ones to choose from across all the shows. Since Past Tense and All Good Things have already been mentioned, I’ll say Time’s Arrow. The hook at the beginning of the episode is just too good. I mean,

spoiler

finding Data’s head in a cave on some random planet while Data is standing right there?

The whole scene with Mrs. Carmichael trying to collect rent… Mr. Pick-ard!

Also, Little Green Men is a great one.

Yesterday’s Enterprise…

No, wait: it has to be Trials and Tribble-ations

@GuyGamer234
"A Quality of Mercy" (SNW S01E10)

IMHO a clever reference to the TOS episode (without messing with the canon) and not the usual "we have to prevent this to save the future" plot.

I was surprised recently to realize that it might actually be "Time's Arrow"-- the more so because I'm not as much of a TNG person as I always thought I was. But Time's Arrow is a fun romp through a nifty and underserved setting, and the ending with Mark Twain is I think one of the most important sequences in TNG.

PIC season 2 has a lot of moments I enjoy. Ito Aghayere's Guinan not being just a 100% copy/paste younger version of Whoopi Goldberg's Guinan, but still being believable as the character. Seven's enjoyment at not being treated and feared like a Borg for the first time in her adult life (life threatening situation from the alternate future aside). Raffi being confused at a mugger wanting "her wallet," and then Raffi mugging the mugger, lol. Really, all of Seven and Raffi's scenes in L. A. after they leave the La Sirena to search for the Watcher.

DSC season 2 finale, "Such Sweet Sorrow." The desperate battle. Admiral Cornwell. The goodbyes, that beautiful scene of Discovery following Burnham, with that magnificent music score. That episode always touches my heart.

DS9's "Little Green Men" s4e8 and "Trials and Tribble-lations" s5e6 are well done fun.

TNG's "Yesterday's Enterprise" s3e15 is great. Whoa, that battle at the end, the Enterprise-D against those Klingon Birds of Prey. I know how it won't end -- meaning an end to TNG, but in the moment it's hard to believe how it won't end.

TAS' "Yesteryear" s1e2. I think it's an episode well worth watching. And, it reaffirms that Sarek and Amanda seriously know how to keep secrets (Sybok, Micheal Burnham), because they must have had some suspicions about how much cousin Selek was like adult Spock.

While those are my favorites, the good thing is that I enjoy the time travel episodes that I didn't list here, too.

Time's Arrow is really fun

TOS: City on the Edge of Forever: Classic time travel story involving morality.
TAS: (haven't seen it, sorry)
TNG: Yesterday's Enterprise: Again, classic time travel story involving a difficult choice of sending people to their deaths in a hopeless situation in order to bring about a better future. Also gives Yar a better sendoff and has the Enterprise-C.
DS9: Past Tense or Trials and Tribble-ations: Another morality focused episode along with an episode that's a celebration of old trek.
VOY: Relativity or Shattered: Seven has to be stealthy and stop a time plot and a kind of a clip show/bottle episode, but in a fun way. Also has someone explicitly tell Janeway to try to avoid time travel, which she obviously listens to.
ENT: Twilight: I think there's a theme going on in my choices...
DIS: Such Sweet Sorrow, Part 2: Let's Discovery do its own thing and it was better for it.
LD: Crisis Point 2: Paradoxus: There's not much to choose from, so the holodeck will have to do. Pokes fun of the movies, in a nice way.
PIC: Season 2: The entire thing I guess, but not exactly my favorite...
PRO: (not sure): I guess the whole thing is time travel related...
SNW: A Quality of Mercy: Limited choices again but it does pretty well at looking at a classic from a different perspective.

I think my favorite is city on the edge of tomorrow! I have no clue what I would've done in Kirk's position but I don't think I would've been strong enough to let her die even if it changed everything

Favourites: Yesterday's Enterprise, Troubles and Tribbleations, Past Tense, Time's Arrow, All Good Things, and Star Trek IV.

Lease favourites: Literally all of the rest.

Perfect list

Favorite: Tomorrow Is Yesterday

One of my favourite as well!!

Yesterday's Enterprise, if I had to pick one.

Some more obscure ones that I like and I haven't seen mentioned thus far in this thread:

I will always pull for Time Amok from Prodigy. It's where in my eyes the series really started opening up. It touches on the deepest themes of Star Trek while still being a fun sci-fi concept.
Terra Firma from Discovery is basically Tapestry, mirror universe edition. Might have worked better as a one parter but it was fun deconstructing how the prime universe had changed Emperor Georgiou.
Timeless from Voyager set some bad precedents for time travel, but it was a good Harry Kim episode.
Shattered is probably where I'll stop any future Voyager rewatches. A fun retrospective on the series, and Chakotay actually gets to do something for a change.

Side note, have we not had any time shenanigans in Lower Decks? I know it's technically coming by way of SNW, but still.

TOS: City on the Edge of Forever - Written by Harlan Ellison with Joan Collins as Edith Keeler.

One of the all-time best episodes of all of trek.

I'll vote for Prodigy's Time Amok.

The premise was really creative and it was delightful seeing the cast work together while not sharing the spot light with each other. And oh Gosh… poor Rok-Tahk.

@GuyGamer234 I love "Future's End" from VOY and "Past Tense" from DS9.

I've always considered time travel to be something of a plot cheat code so such episodes aren't often favourites. But that said we've been watching Enterprise lately and recently got to S03E11 "Carpenter Street" and it had some good moments.

Top of mind is Archer driving a truck and T'Pol exclaiming "Turn Starboard at the next street!"

Incidentally I'll never understand how they could possibly think taking an alien back in time to Earth is a good idea. T'Pol is the second last crew member that should have been on that mission (just slightly ahead of Phlox)

Relativity and if we somewhat widen the definition, Shattered.

Trials and Tribbleations, and Little Green Men.

(the goofy ones, I know, but they are my favourites)

I just love trials and tribbleations. The glee of the cast is just so lovely as well as the near seamless integration. Least favourite, to stay with ds9, is little green men because it was too predictable

Time's Arrow (Part 1 & 2). There's nothing like Data being the pimp he is. Picard meeting Guinan.