I think both have their appeal, but it's easier to timebox the enjoyment of a play. It's also easier to discuss, or think about.
I felt like it was a bit too much of the social stuff, maybe because it plays mostly on a station instead of an exploration vessel, but I guess that is exactly what people like about it. The characters and their development and so on. I liked the Garak character for example, but disliked Zisko being some chosen one for the wormhole gods or something. I much prefer Data, or Picard or most of their crew, even if they don't develop as much.
Well, to each their own, they are all good series to watch.
TNG is a classic, with the classic crew and after the first hiccups is some of the best scifi of all time. Absolutely great actors and amazing writing.
DS9 is the weird one. I do really enjoy the trajectory of many of its characters: Sisko, Odo, Bashir, Dax (one of my favorite characters in all ST), O'Brien, Quark, Kira, Worf, Dukat, Garak, Damar... The list of great characters in DS9 is the best part of this series. The last season was a definite letdown for me though, and I didn't like the ending at all.
Voyager was the surprising one. I expected a lesser series after reading the old discussion about the three Treks of the 90's. But wow. It's banger episodes right from the start, one of the most badass captains in all of Trek and in the fourth season arrives my favorite scifi character: Seven of Nine. There's a lot of great episodes here, and some filler. I didn't like how some characters never went anywhere. But there is more good here than mediocre. As a series I like it more than DS9, I just wished the other characters were up to the writing of Janeway, Seven and Doctor.
I won't claim my taste is universal: it's just something to be aware of.
Stargate Atlantis: Maybe better than average. On rewatch it's tended to feel bland somehow. Began with SG-1 S8 and ran concurrently with some crossovers (Atlantis premiere happens immediately after SG-1 S8 premiere and contains minor spoilers for it).
Stargate Universe: Nope. Had potential it very much did not live up to. Set years after the first two ended.
Stargate Infinity (cartoon): No way. Additionally was made before SG-1 got very far and has many incorrect guesses about how it would have developed, set decades into the future.
I think that's probably why a lot of people don't like it, the bad outweighs the good for them.
* Before some recent entries at least. Yikes.
Luckily Lower Decks was good, Picard had some good moments and there were a few good episodes in Strange New Worlds too, even though that series didn't really excite me anymore in its latest season.
Voyager's bad episodes are still better than most of the scifi I've watched in the recent years. They are cringe, but in a funny way.
And no, I'm not sorry for reminding anyone that this episode exists.
Because clearly none of the other series focused on social stuff, except...
TOS, which featured an interracial cast (and kiss) in the 1960s, where nearly every episode was thinly-veiled commentary on communism, where they visited a literal Nazi planet, where they had a black woman as a bridge officer (in the 1960s)...
TNG, which went into deep moral arcs, looked into military tribunals, witch hunts, had entire movies about mindless bloodlust and environmentalism/colonianism, and so much more...
VOY which.....honestly, if you don't get the point by now I'm not going to spend more time listing examples.
Star Trek was BORN "woke" and has always been there, and anyone who claims otherwise was never really paying attention. Star Trek EXISTS because Gene Roddenberry put social commentary into his show "The Lieutenant" which was too controversial for the actual US Military so he had to make a new show set in the future to make all the same points but with less oversight from crusty generals.
PS: Did you forget TOS in your lists or leave it out intentionally? IMO it focuses on doing one mostly self contained short story per episode even better than TNG.
It's also crazy how relevant to modern times the plot of B5 is and how many parallels you see.
The series creator and chief writer, J. Michael Straczynski was explicit about that: The Earth Government story arc is lifted straight from the fascist regimes of the 1930s and 1940s.
A significant amount of which we're seeing rebranded as MAGA in the US and other far-right movements elsewhere.
A good example would be the "anti-alien" frenzy in Babylon 5 as compared with the far-right's ridiculous tropes about the undocumented in the US.
There are a bunch more like Trump's obsession with personal loyalty and lack of any empathy is quite similar to Babylon 5's President Clarke.
As I mentioned, that story arc is based upon the fascist regimes of the '30s and '40s, they even have a "Neville Chamberlain"[0] analog[1] who loudly proclaims "Finally, we will at last know 'peace in our time'."
The biggest difference is that in the Babylon 5 universe, the fascist scum are much more competent than those IRL today.
There's lots more, and I'll echo the plaints of others here that Season 1 is uneven and appears meandering, but many of the plot points brought up in Season 1 end up paying off much later in the series.
I heartily recommend watching the series, not just for the parallels with some of our current circumstance, but because it's a good story with the entire five season story arc fleshed out from the beginning, with good character development and character driven story lines.
It was also the first live-action Sci-Fi series that made use of CGI for the space scenes, which was both very cool, but was also limited compared to today's SFX given that 30 second segments could take hours to render on the Unix workstations of the mid 1990s.
Is it perfect, no. But it's worth the effort to watch it IMNSHO.
DS9 has some wonderful episodes and fantastic characters, but the overall plot was weak. The world building was plot driven while in B5 it is vice versa and it made all the difference for me.
I doubt that the changelings and the dominion where planned from the beginning.
DS9 very quickly brought in the Defiant so that its characters could escape the station and go on more traditional Star Trek adventures. The station was home base, but the crew got out a lot. It typically felt like the station was well under control, with only minor differences between it and a star-fleet vessel. (Toss Quark and Garak out an airlock and you'd pretty much have a standard starship.)
B5 did send its characters on excursions, but they were fewer and far between. The station was not a safe home base. It was a bigger and wilder place than DS9 ever was. It always felt like some crisis or another was ready to spiral out of control and the staff generally needed all hands on deck to deal with whatever was happening. DS9 had the occasional crowd scene, but B5 had bigger crowds (in record shattering amounts of alien makeup) every episode. DS9 felt like a sleepy frontier fort. B5 felt like a city.
Then there's the continuity. There just wasn't a lot of continuity in anything other than soap operas in the mid 90's. TNG occasionally had multi-part episodes and sometimes referenced earlier episodes, but it was always careful to explain things so you could jump in anywhere and not be lost. DS9 was initially episodic, but had some larger arcs in later seasons, perhaps as a response to what B5 was doing. B5 broke the mold. The first season seemed episodic at first glance, but each episode advanced the central story-line. You could jump into Season 1 at any point and be a little confused, but figure things out. That swiftly changed. Later seasons became completely continuous, and frequently relied on bits of story that happened in earlier seasons without any kind of hand-holding. This caused big problems that probably prevented B5 from being as well received as it should have been.
This is for the young whippersnappers out there who grew up with the internet, streaming, and home video: Today, if you decide to jump into a show, you can call up every episode on demand. If it's not on a streaming service, it's on DVD or VHS. Failing that, there's always piracy. When B5 came out, it was not a given that a TV series would be released on VHS or DVD. The internet was there, but it wasn't yet up to distributing video. There was no such thing as streaming. The era of Netflix mailing you physical discs was years in the future. If you wanted to watch a TV show, you had to tune in when it was broadcast. It was, essentially, live TV.
The kicker is that most broadcasters were utterly irresponsible in how they aired shows. Episodes would frequently be pre-empted or aired out of order. Broadcasters were used to purely episodic content. Who cared if people saw episode 5 before episode 2, or missed episode 3 until it got reran the following year? This royally fubar'd people's ability to follow B5. My personal memory of B5 when it first aired was fragmentary and frustrating. I'd watch an episode and really enjoy it, try to tune in next week only for it to be pre-empted by golf, and then be lost when an episode from much later in the season was aired the week after that. It wasn't until B5 came out on DVD (years later) that I was finally able to watch the show in order and finally appreciate how special it was.
Continuity between episodes is normal now. Everyone is used to shows that play out as one long narrative instead of hitting the reset button every week. B5 blazed the trail for them before TV distribution was really ready for continuity. There are a lot of warts to overlook. CG was in its infancy back then. DS9 was still using physical models in its first few seasons. B5 looks like it came out of somebody's Amiga because it literally came out of somebody's Amiga. There probably won't ever be a quality up-scaling of the special effects because a lot of the files from that Amiga were lost. The set design is clever, but stagy. The budget of B5 doesn't even add up to half a shoestring by modern standards for a show with 10 episodes a season, and B5 had 22 episodes a season! The story is so grand and detailed that it still feels rushed at times. (They thought the show would be cancelled at the end of S4, so they crammed most of S5's plot into S4. The result is fantastically dense and frenetic!)
In the end, DS9 was a fantastic show but felt a lot like the station featured in it. It was always well under control and its creators got everything they needed to deliver a compelling show. They knew how far to reach and chose their battles wisely. B5 feels like a wild and overreaching fever dream by comparison. It nearly span out of control, much like its titular station was always threatening to. If they decided to re-make B5 today, they'd probably simplify it immensely. It's story still seems too ambitious for a single TV series to tell. If you can get past the warts, B5 is still a unique and rewarding series to experience. Nothing quite like it has come along since.
It actually feels more like most shows make things up along the way for each episode or at least each season, always trying to one up previous universe-shattering changes in order to give the audience their dopamine hit. While the continuity was well done in B5 it's been mostly a disaster for the industry afterwards.