I recently started watching Star Trek and have finished every series other than TOS (and Prodigy).
I had been putting TOS off since it initially seemed pretty cheesy so I had planned to skip it entirely. After finishing everything else, though, I decided to give it another try.
Now I’m about two thirds of the way through, and I’ve actually found it quite enjoyable. Also Bill Shatner is a better actor than I gave him credit for. I had always expected a very hammy performance based off the way people talk about him; but considering he was being watched on like a 12 inch screen, I would say his acting was actually rather subtle.
Also the practical effects look surprisingly good. It really goes to show how much better they can age. There are some shots of the ship('s model) that look comparable to modern CGI in my opinion.
I would not say TOS is my favorite Star Trek series so far, but I would put it in the top 5 for sure.
I highly recommend it. I think it gets a specific negative geeky reputation associated with it, but I found that reputation to be unfounded.
For most Star Trek series, it is a very forward thinking show that deals with a wide array of morality topics. Even cinematography/ effects wise, pretty much all of them other than TOS feel very modern.
I don’t think I could recommend a good way to get into it, but I will say I started with Lower Decks, and the obvious love the writers had for the franchise encouraged me to look at the more traditional series as well.