My thoughts (I have not watched much of the new stuff)
TOS- oh boy, there are some of the best Star Trek here. Absolute classics like The City of the Edge of Forever, Balance of Terror, Journey to Babel, The Trouble with tribbles, Mirror Mirror, Amok Time and Let that be your last Battlefield. But then it also just have some of the worst Drek. And no Spock's Brain is not the worst Trek episode, because at least Spock's brain is funny. And there is so many things in TOS that's just creepy, usually because of Roddenberry. Seriously, screw Roddenberry.
TNG.... -okay, TNG is great, but also there is the first two seasons..... Especially Season 1 is a hard watch with alot of pure Drek. Season 2 is a little better and has classics like Measure of a Man. From Season 3 onwards TNG is mostly good, but each Season has some Drek you just want to skip. Actually TNG started to get better once Roddenberry was "kicked upstairs". Imagine that.
DS9- my favorite, an alternative take on Trek that still fits within the universe of TNG. DS9 i the show that goes alot into the politics of the Federation and various alien civilizations. It's the most continuity driven off the old Trek shows. It's not perfect but it's vvery much my Trek show that I enjoy the most.
Voyager- I feel Voyager should have been good. But there are many things hampering it. A weaker cast, trying too much to just be TNG, basically wasting the premise of being a lost Federtation ship far from home, often blamed for making the Borg lame, but the problem here is the Borg was always inevitably becoming lame, because the more you show them the lamer they get. Voyager was a show with potential, but the writing wasn't there. It has some good episodes and moments, for sure.
Enterprise: Oh man, alot of it unfortunately just sucks. Many characters are just written inconsistently and often quite bad. Many of the stories are just weak, even though there are good premises. Archer being a bumbling idiot would be great, if he was actually written to be a bumbling idiot, now he comes of as an idiot because bad writing and characterization. The era of Pre- Federation humanity, and the human first steps into the Trek universe is great on paper, but then most of the show instead becomes a jumbled mess of a "Time War", where they fight aliens called the "Sulibans", because it rhymes with the Talebans I guess. The Time War storyline never really gets a satisfying conclusion, and is basically ejected by Season 3, that has the Xindi arc, which has some good episodes, but also unfortunately loads and loads of Drek. And let's not wven talk about the Nazi Aliens. Season 4 though is actually good. My recommendation is: just watch Season 4 (from episode 2, episode 1 is just tying up the mess Season 3 left the show in with the darn Nazi plot).
I haven't really watched the new stuff, except Picard season 1, that started interesting, but then just became really bad.
But about new Trek, I know people yell about it being WOKE. However these people has never watched Old Trek. Old Trek is WOKE as ****.