I’m going to say any or none of the suggestions here may be right.

And some of them, like Inner Light, are awful choices simply because their impact is very dependent on having the context the rest of the series and characters.

The main thing is that Star Trek has a wide variety of tones. The way to success is to provide excellent examples of very Trekie episodes that are in the genre or tone that your brother already likes.

Don’t show them action if they like cerebral mystery. Don’t show them romance if they like action. Don’t show them intense drama if they’re into comedy. If they’re into animated comedies or anime, start with Lower Decks or Prodigy not TNG.

Examples from this perspective…

If they like psychological horror, then TNG’s ‘Schisms’ or Voyager’s ‘The Thaw’ might be best.

If they like action, Discovery’s two part pilot might be the one or even the movie Star Trek (2009).

If you are talking TOS then for me it's "The City on the Edge of Forever".

DS9 The Visitor is a complete story on its own and has some of the best acting in the franchise.

SNW "A Quality Of Mercy"

and then TOS "A Balance Of Terror"

The SNW episode retraces events of the famous TOS episode it is very cool.

I think it conveys the breadth, depth and love there is in the star trek fandom for the universe.

I've struggled with this question for years, and haven't been able to come up with an answer I feel good about, so the "correct" answer is probably, "consider the person's tastes and cater to them."

I do believe that it's probably not a good idea to start with the "best" episodes - they tend to break the usual format, and once you've seen them, there's nowhere to go but down.

Instead, I'm on a continuous search for the most "average" episodes - solid, enjoyable, and representative of what the series and franchise are as a whole. But I still don't have a simple answer.

TNG, “The Inner Light”

TNG "Devil's Due"

Top notch in my opinion. When Picard steps to The Devil (Ardra) is one of my top moments of all time.

I think lots of people could identify with this episode due to it's scifi content and it's theological content.

I think the first three episodes of SNW are like made for new people with showing clearly what Star Trek should stand for.
If you are only watching one episode to hook him in you could also go with something funnier like lower decks or a ferengi episode

Or you could get confusing and take The Orville :p

By series: TOS: City on the Edge of Forever TNG: Measure of a Man or Inner Light DS9: In the Pale Moonlight or The Visitor VOY: Scorpion SNW: 1:1 or Memento Mori LD: Crisis Point

Don’t show him any of the all time greats. Then there’s nowhere to go but down.

I also wouldn’t try to hook him on a twenty or thirty out forty year old show when there’s a really good Trek series coming out right now. There’s no urgency to watching an old show, so even if he likes it he’s likely to put it off for later and forget about it.

Just hit him with SNW episode 1. It’s a decent episode, not an all time best but a good introduction to what the Federation is all about and very briefly how it grew from the present day. And if he decides to continue in his own, there’s no question of where to start - just move on to episode 2.

Voyager’s “Year of Hell” is the best of any television, but admittedly, will be a difficult entry. If they are adventurous, though, it’s fully enjoyable without any Trek knowledge.

Darmok

DS9 - In the Pale Moonlight

Hands down one of the best storylines, acting, twists, pure joy of resolution.

@neon_nova _Tapestry_ is my favourite all time episode, but you need too much back story for it to work. _The Most Toys_ has always been in my top three.

@neon_nova it comes down to either 1. The Drumhead 2. Code of Honor

I personally love DS9 and think that it has aged better than TNG. I think its S1 is not amazing, but certainly one of the better first seasons. It has plenty of good enough episodes that don’t depend heavily on the upcoming plot and leave your brother in a good place if he wants to start watching for himself.

A few suggestions would be:

• In The Hands of the Prophets: Overall an almost prophetic episode, in the most terrifying way possible. A well-done drama episode with great political commentary. A lot of the season built up to it, but it’s such an early period in the show that it’s not TOO much context
• Dax: A full helping of everything Trek, from alien trials to crew collaboration to space mysteries. It basically explains the Dax thing for you, just leaving an interesting story. Vortex: Odo-focused, but also has some “crew on space mystery” bits. Also makes a mystery of core information in the show, meaning minimal canon dependency and once again leaving your brother in a good place to watch.
• Duet: Strong Kira episode that’s also a good summary of the Bajoran-Cardassian conflict.
• Captive Pursuit: I think it’s a solid, typical Trek episode. I think the only impression issues it might give are it’s very O’Brien-centric, and it might register a bit on the “aliens who represent no particular real life ethnicity but are still kind of iffy”-o-meter. But otherwise, it’s a low-canon, medium-quality episode.

My first inkling is to always tell someone to just start from the beginning with “The Cage”.

But if I have to pick something else my mind wonders to “Cause and Effect”.

Might be a bit off beat to say this, but maybe the first episode of Prodigy?

It's very much intended as an entry point into Star Trek for those unexposed to Star Trek.

Also "Duet" from S1 of DS9. Incredible acting.

@neon_nova

That's not really they way to experience Star Trek.

Unless they are already into SciFi or Morality Tales picking one episode won't work as an introduction.

Each series and season has a different style and presentation 🙂🖖