Star Trek's run in the world of science fiction and entertainment at large has seen the franchise create 10+ shows and counting. That's a lot of shows, even across a 60-year time span. That's a lot of ups and downs. A lot of good episodes and bad, and a lot of series that range in quality. It'd be hard to really nail down a favorite show among the fanbase.
Many fans will say Deep Space Nine or the Original Series or The Next Generation, but every show has its merits for why it should be considered "the best". There's really no wrong answer, except for maybe the Animated Series, but even that show has its defenders.
Yet, when it comes to aggregate sites like Rotten Tomatoes, there's not so much "opinion" on the best, but bonafide stats that claim the best. These are still based on opinions, so take them with a grain of salt, but the website does boast one series above all else.
That series is Star Trek: Strange New Worlds, which boasts a critic score of 98% (but a fan score of just 79%). So, with its high rating, is it the best Star Trek show around? No. Or maybe yes. It's a subjective answer. Whatever show you like the most is the best Star Trek show around. Yet, if you're looking for more of an answer, and not so much a critical introspection introspection on the idea of quality within an individual, then we may have one for you.
I think critics are the worst people you can gauge entertainment off of. They're often times either paid by the property to review said property, or they're only given a limited view of a show. Say, for instance, the first three episodes. A show could get really repetitive and boring after three episodes. Thrilling storylines could come to a crashing halt and peter off, ruining the experience for everyone.
Critics wouldn't be able to judge a show in its entirety, yet they're given priority on the website. So when I look at Rotten Tomatoes, I much more care about the fan scores. Which, Strange New Worlds doesn't do that well with.
Of all the shows, The Next Generation has the highest audience score of 90%, which to me carries a lot more heft than some critics who only watched three episodes of Strange New Worlds before giving it a score.
Considering that Strange New Worlds has had all of 20 episodes released, there's no way anyone can argue that they're really the best show. Even if all 20 episodes hit for you, which they won't, there are other series with far more "good" episodes than Strange New Worlds has. So yes, I'm going with the idea that the "best" Star Trek show on Rotten Tomatoes is anything but.