It's all personal, I guess. The way I see it, TOS was just about state-of-the art for what it did: it was just about as serious a show as the other dramas of its time while being the first show to seriously grapple, week after week, with a mostly coherent space opera setting. It was revolutionary and, I submit, responsible for the a great deal of the mainstreaming of SF that is all through our cultures, high and low. And even then, only about a third of its episode were of the of the quality that makes me say, to this day, "My God, but I love that show!" TMP and TWOK each had a measure of that but after them, Trek became "product" and rarely showed real inspiration. As a fan, I was willing to blind myself to that--I adored TSFS and TUC, for example, when they hit theatres but can barely watch them today.
But yes, I did derive a lot of enjoyment from DS9. Hell, back in college, I got a big kick out of TNG episodes I cannot tolerate today. And
I was abou 9 years old when I first became a Trekkie--no doubt, I'll be more kind to stuff from back then out of nostalgia. But I can't ramp up that passion for Trek anymore, nor do I think I should try. For a while I was here, fighting the good or not-so-good fight against the overly optimistic projections but I can't really get it up for that any more, either. This next movie is just a movie, it'll suck or not suck on its merits. I just hope I can judge it thusly.