Well, I grew up with TOS and it will always hold a special place in my heart. I remember watching the first moon landing on TV in 1969, and the film 2001: A space Odyssey had been released the year before, so TOS was, in a way, a weekly beacon of hope for all 13-year-old's who yearned for the stars.
I was unsure how I would react to TNG when I heard it was to be aired, but I was hooked when I saw the E-D - I just love that ship.
I liked Picard but Riker and Data looked very young, Troi just baffled me and Geordie was cool with his Visor. The only thing I found kinda lame was the reveal of the 'jellyfish' aliens, and even more so, when they 'held hands' at the end.
TNG is, I confess, my favourite Trek series.
I liked DS9's darkness and the interplay between a good number of strong, self-willed characters. The over-arching storyline was also a welcome if, unusual, departure from the previous series. Overall, I enjoyed this Trek experiment.
Voyager, on the other hand, was more difficult to deal with. The initial premise of the show seemed just a little too contrived. I had no real problem with Janeway. It was a brave attempt to introduce a female captain as the lead in a new Trek show. For all her failings (blame the writers for that) I think Kate Mulgrew did a fair job, but there were at times I thought I was watching Katherine Hepburn (very famous 1930's to 1980's actress).
My favourite character was the EMH. Robert Picardo, what a delight, the rest of the cast were very 2D. A good enough series, but nothing of note for me.
Enterprise......

What a wasted opportunity. As soon as the title song started I knew it was gonna be a turkey. Nice song, but no way was it Trek. Even the opening titles and visuals seemed more like a feature on the Discovery Channel.
I suppose the big giveaway that this was going to be a horrible car-crash of a show was that the precursor 'Star Trek' was missing from the title. Even RS and BB knew that it didn't deserve that accolade. It was only when the ratings bombed that they added Star Trek to the title in a vainglorious attempt to legitimise this stillborn abomination.
I liked the characters and the actors brought depth to them. I thought Scott Bakula was very good as were the supporting cast. Jolene Blalock had the most difficult task - to be portray her character with 'gravitas' and also to titilate the schoolboys. T'Pol was a reincarnation of Seven of Nine - A cold, unemotional, uncaring, sexually naive hottie just waiting for a full-blooded human to show her what she was missing.
And don't get me started on the 'Enterprise' Akira-class refit - what a swizz. No originallity and no reference to the TOS 1701.
I guess you have figured out by now that I didn't like Enterprise, but I have found a solution to my dislike. Enterprise is not Star Trek, it is simply a nondescript, half-way decent Sci-Fi series that ripped off a whole load of Trek ideas. If you watch it in that frame of mind, its not so bad.
This is not my thumb...

It is the bandage that used to be on my thumb.