I like all of the Star Trek series (even the ultimate fan un-favorite, Enterprise.) They all have their great, good, not-so-good and absolutely wretched episodes, but all shows have that. Though, TNG & TOS tie as my favorite of the ST Series, with DS9, Voyager and Enterprise (in no particular order, so I stuck them chronologically by production) lagging slightly behind those two. I also like a couple of the internet fan series, Phase II (formerly known as New Voyages) and Starship Farragut. I need to check out a couple others.