Right, hand over your fan card. DS9 is unmissable

Well, DS9 it is then. I know it's hard to survive the first two seasons, but it'll be worth it.

I’m convinced that many people don’t appreciate DS9 until their 30s.

Cool that the 90s shows each seem to appeal to different demographics even though they were all in theory designed for mass audiences ( unlike in the current streaming era).

The problem seems to be that a lot of younger fans that get into Voyager & TNG, just cringe at DS9 or find it boring. Once they’ve had that experience they’re hard to convince to give it a fresh shot when they’re older.

I think many of us feel that DS9 is one of those shows where each season is an improvement on the one before it. So it starts out pretty mundane at best with some terrible episodes, but by the final season it's pretty incredible.

My two-cent hot-takes on that list of shows:

• Stargate: For the time, it did the Trek format incredibly well if not better. First season was rough, but oddly found its feet when SciFi took over (weird, right?) Good characters, great villains, fantastic arcs. The show "ends" multiple times, with the last few seasons being less than fan favorites. That said, if you love the characters by the end you may find yourself putting up with late season plot devices. Atlantis is good too, but shorter with slightly less compelling plot hooks. The short-lived SGU sequel/spinoff is has this man-v-man flavor not unlike DSC season 1, but doesn't stand on its own lore-wise.
• Babylon 5: The even more grounded DS9. But like the oft-compared Trek series, the production values are a 1990's time-capsule, which (today) has a kind of charm to it. The story arcs center around diplomacy, subterfuge, spycraft, and interstellar war, all told in a universe that is delightfully consistent and charts its own territory. Characters play off each other incredibly well once the series gets going.
• Galactica: I'm going to assume you mean the reboot*. This is a gripping serial epic with very few filler and bottle episodes. Characters grow and evolve, allegiances change, motivations shift, ethics are challenged, and whole personalities get re-written. You can slap "space opera" on the box and be correct, but you can't describe more than two character arcs without filling your mouth with crazy nonsense. Yet somehow, it all works brilliantly and draws you in over and over again. It stands apart from the source material, but has lots of nods and references to the original so that the old farts in the audience are enthused.

(* The original BSG is a hot mess of amazing-for-the-time effects, cool characters, great concepts, and bad studio interference. Best enjoyed using mind-altering substances because that's clearly what the writers were doing)

My brother in Christ...

WATCH STARGATE!

It is probably the most well-rounded sci-fi ever made. Very good characters, very funny, and the budget kept getting bigger with each season. (Probably should've stopped after season 8, the whole Ori plot feels tacked on - it's still pretty solid, though.)

There are a lot of familiar actors throughout the series, including some from Trek.

• You don't need to watch the original MGM movie, it's technically set in a different universe. But it is fun. And the events of this movie are explained in the series as needed.
• Do make sure you watch the R-rated version of the series pilot (Stargate started off on HBO)
• And don't forget to watch the two TV movies set after the end of the series. One is okay, the other is excellent.

....When you're done with that, then you can watch Stargate Atlantis which has even better characters!

I really liked Babylon 5, I'll say it gets REALLY good around season four. Season five is a little bit less good but it isn't bad

For the final season of the Expanse, I'll try not to spoil anything but I'll say that Covid has once again given me a reason to despise it for what it did to the ending