I voted Original Star Trek, and I’m finding it difficult to express why. More of feeling than anything I can rationalize. I think it’s because I grew up with it. I was 23 years old when TNG first aired, so for me the Kirk, Spock, NCC-1701 Star Trek had already settled into my psyche. (Yes, yes do the math …I’m older than most of you GWCers.)
Watching TOS now, it’s hard to not raise my eyebrows at the Shatner overacting, but when I was I kid that just seemed the normal way a starship caption would behave and talk. (Don’t get me wrong–Shatner is awesome, so I don’t mean to diss him.)
Mind you, I’ve watched every episode (I think) of every series (might of missed a couple DS9s).
All that said, I think TNG has most number of good and great episodes.
As for DS9, yeah it was well done and everything. But for me, a key part of Star Trek is the “trek”. In other words, I like to seeing a ship and a crew trekking through he stars.
I enjoyed Voyager, but, if it were up to me, I wish the series involved more desperate situations driven by being all alone so far from the Federation. If, by the end of that series, the crew and ship where totally changed by their ordeal I would have been happier.
Enterprise? I think the ideal of it. I liked the characters just fine. But I think they missed an opportunity to get into stuff leading up to before the Kirk days. The whole Xindi arc I could have done without. I would have liked more of the “arrive at an undiscovered planet” kind of story. Dealing with the consequences of pre “Prime Directive” thiinking would have been interesting.