I grew up on The Next Generation, so I have a soft spot for it. Patrick Stewart wins at everything he's in.
Despite its occasional hokeyness and overkill on filler, I liked Voyager a lot for the simple fact that I liked the premise and the characters. Voyager struck me as one of the more character-centric of the Star Treks, while I like. Neelix and Kes can die for all I care, but the rest of the cast tended to be pretty good (the Doctor!).
DS9 was okay, but for some reason I never got into it as much as TNG or Voyager. It had good characters, and there were some good episodes, but I just fell out of watching it for some reason. Plus the politics in later seasons bored me.
As for the other two... Never watched the original series. And I've seen maybe six episodes of Enterprise, every one of which I hated. Enterprise characters annoyed the hell out of me.
Oh, and in honour of the 40th, check out this
Wil Wheaton episode review if you have some time to kill. He said in
his blog that he's going to be reviewing TNG episodes in honour of the 40th anniversary, so this is hopefully the first of many. And it's hilarious. First sacrificial offering: "The Naked Now". It's one thing to read a review of a bad episode. But it's even funnier to read a review of a bad episode from someone who had to
act in it.
Jam it back in, in the dark.