Um, three out of five, really. TOS, TNG, DS9, they's all good. The last season of Enterprise, even, had a whole bunch of good stuff in it. Voyager... not so much. But I still watched quite a bit of it.
I am not sure I look forward to the new movie, though...
My favorite Trek is DS9. I enjoyed the character development and the fact that you had characters that were not quite as squeky clean as Next Gen's characters. I felt that the characters had a lot more room to grow.
I enjoyed the fine line Sisco had to walk between being a starship officer and a prophet of the Bajoran faith. I really enjoyed seeing the real development of two alien cultures that Cardassia and Bajor got.
I enjoyed watching Voyager I enjoyed the characters and I will admit it I lusted after Robert Beltran as Chakotay.
I grew up on TOS. It was because of tOS that I started reading sf novels. I still enjoy watching the series today as much as I did back in the dark ages. My favorite Trek movie is the Voyage home closely followed by The Undiscovered Country.
I enjoy the Animated series and the New Voyages.
I never really got into Next Gen and its sterile ship and crew. The characters were so squeaky clean and did not have much room for development.
Hmm ... I really couldn't vote for any of them. I tended to like individual characters in whatever the series was as well as individual episodes. And certainly none of them were "I MUST watch this week's episode!" sorta things for me.