Watching the final season of
Star Trek: DS9, and wow what a ride!
Deep Space Nine is the third(i think) incarnation of the Star Trek tv franchise, the last series for me to watch, and i must say it gives voyager a run for it's money as my favourite.
Dominion war is pretty bitchin' and i must say out of all the treks, i feel like the writing is the best for this one. So many good episodes, and truly excellent performances from the cast all-around, not to mention some great comic relief, particularly from some lesser-seen-yet-great alien characters like Garrak or Quark's Brother.
Another thing i love about ds9 is they have some really great "filler" episodes. Some of these standalone shows--that has nothing to do with any of the main story arcs-- had some of the best/meaningful performances of the series(sometimes from the most unlikely of characters), and are among my favourite episodes.
Voyager was more about survival, tough moral decisions, unfavorable situations, and techno-babble. The number of opportunities they passed up to get home annoyed me, but it's a great series. The last episode of voyager in particular was a damned great episode. I like how that episode framed it so that they could end the series whenever they wanted.
TNG was more about social/moral issues, and contact/tolerance with other races. It introduced the holo-deck, which was a pretty brilliant idea. It allowed them to explore ideas/locations in any setting they wanted. It's a damned solid series, but I wish Barclay had more episodes.
Enterprise sucked for a while, but it got pretty good towards the end. It was probably the only star trek series that I hated any of the actors in. It would've been significantly better if T'Pol wasn't there (although she was hot), and if they didn't try to ret-con giant history changing events into the Trek rhetoric (The Xindi weren't mentioned in any of the future trek series.) It did put star-trek technology into perspective though; It was the only star-trek that really showed any grit or inconvenience in their daily lives. I think they even showed a bathroom! The others were all about using well-established "science!" to accomplish things with minimal effort. I enjoyed the fact that they didn't have replicators. Also, Shran was awesome.
tldr; You should all watch Star Trek. Start with The Next Generation if you are new.
I'm not saying don't watch the earlier ones, just expect some noob ahead