Babylon 5 was a great, but flawed show, but probably hasn’t aged well in a lot of ways. At the time, a lot of what it did was groundbreaking - story arcs, essentially the entire series is a novel set to 5 seasons of TV, a cynical sci-fi universe, all-CGI special effects, a creator who had enough control to create his vision, some other stuff. Some of those things have become more widespread and refined, which might make some of what B5 did look crude. Battlestar Galactica, for instance, from what I hear, probably refines a lot of ground that B5 paved.
And compared to its contemporary competition as far as sci-fi TV went - it came after TNG and alongside DS9 (which intentionally stole a lot of elements from the show - a lot of what makes DS9 the best trek show, the more realistic, gritty universe (relative to other star trek shows), the story arcs, etc. were taken deliberately from B5) - and was far far better than those shows.
There’s almost no technobabble - actual stories are told within the context of a sci-fi universe, rather than some nonsense unsatisfying technobabble creating a problem that nonsense unsatisfying technobabble later solved. The universe is much more interesting, darker, grittier, and believable. No preachy humans who’ve become the pinnacle of the universe and sneer at us 21st century barbarians.
When compared to something like Galactica, it’ll look old and somewhat cheesy. Compared to something like Star Trek the Next Generation, it’s great.
On the downside, there’s a lot of crap, especially at the very beginning and very end. Some of the early episodes of B5 like “infection” and “tko” are not quite Spock’s Brain, but they’re pretty terrible. Early on in the series they were using different writers, but towards the middle, as episodes were more and more devoted to resolving the main stories, they were written pretty much exclusively by the show’s creator. Not that everything he wrote was gold, but it’s a lot less hit or miss.
The dialog can sometimes be very theatric and unrealistic. There’s some cheesy stuff all over the series. The show was always facing cancellation and studio interference, and the story, which was mapped out before a frame of film was ever shot, needed to be adjusted - whether it be by studio-mandated cast changes, or accelerating the resolution of the story at the end of season 4 because a season 5 wasn’t expected, etc.
Overall, though, keeping its flaws in mind, and forgiving some of the early horrible episodes (which I can’t recommend skipping entirely, because they contain stuff that relates to the overall story), it’s really a great show. It sets out to do so much, and hits on a lot of it.
