What I see here are a lot of people dismissing TOS based on things that were "of its time." Honestly, you can't judge a show with the social standards 45 years after the fact. Yes, it was chauvinistic. Yes, the effects were primitive, yes the acting was more stylized, yes everything was awash in bright colors. So what? Look what it did: it presented science fiction to the masses in an adult fashion. It didn't aim for the 5 year olds. Instead it tried to reach audiences by having respect for their intelligence. At a time when sci-fi on TV was considered kid's stuff, Star Trek aimed higher and still had fun doing it. Was it a good show? That is a stupid question - time and society have already judged Star Trek and its value. You don't have to like a show to admit that it's good. I hate I Love Lucy, but I respect it and its quality. It just wasn't my thing.
I find it hard to understand why so many people just can't or won't watch a show in context of its time. You cannot judge classic Trek by today's standards. To truly appreciate it, you have to set your mind on "60's" and just watch. You don't have to like it, but shutting it out because it's "outdated" is narrow minded. Twilight Zone and The Fugitive don't get this kind of grief and they are both very much of their time. You can't judge TOS for not having "Story arcs." That just wasn't what they did in the 1960's. Every episode (unless it was a two-parter) was self contained and resolved at the end of the hour. Star Trek was FAR from the only series like this. Every show was, unless it was a soap.
TNG was also an excellent show. Once it became what it had to be (its own show, not dependant on TOS), it was amazing, The middle few seasons were incredibly good television (the third season alone had, by my standards, a 99% success rate). It doesn't matter that the feel good 80's put Troi on the bridge, or that many of the effects fell flat (model effects were too expensive and CGI wasn't all that good yet so they didn't use it). It told good stories, had good characters and actors, and expanded the Star Trek universe in very important ways.
There are a lot of stupid episodes in every Trek series. Both TOS and TNG were brilliant. Was one better than the other? I don't think so, they both did a lot for SF TV and beyond. There are the two best Trek series made. Which one you prefer is your own choice. But you don't have to insult one to love the other.
Why are TOS fans so defensive? It wasn't a TNG fan that started this divisive shitfest of a thread.
Be careful not to generalize. There were a lot of TOS fans who were glued to their TVs the night Encounter at Farpoint premiered. We stuck with the series for the entire run, gladly. Lots of us just enjoy Trek in general.