I hate to say it, but all things considered, DS9 was the best show.
Growing up, I would have said TNG hands down. My favorite characters are all in it, and the adventures they go on are incredible and entertaining. As an adult, I can even watch it and learn a little bit about what humanity needs to overcome, and what ideologies need to be placed on the way-side for the sake of human progress.
All that said, DS9 is still a better show to me. I stopped watching it after TNG was canceled, because I was only really watching it because it aired right after TNG, and it was still Star Trek. Now that I've seen the whole show from front to back, I think I enjoyed it more than I did with TNG. I question how much I'd like it without the background of TNG, and the universe it explored and created, but as I experienced it, it had the best character development, the darkest themes, and was focused around a very intense political conflict that I think was better than the random one-shots that TNG offered us. It just ends up being a better show in the end, even if the adventures aren't quite as grand.
Spade Lead said:
Do yourself a favor and watch TNG front to back, and then follow it up with DS9, front to back. DS9 takes about 3 full seasons to become truly engaging, but TNG takes probably 2-2.5, so it's just par for the course I guess.
Your story reminded me of my expereince with DS9. I decided about 6 years ago to start watching all of Star Trek, and so I made it through TOS-DS9. I eventually caught up on Voyager, but I hated almost all of it (Season 2's Threshold has to be the lowest point in all of TV history, even counting Jersey Shore). I'm repeating the same cycle again this year, because my roommate has not seen any Star Trek, other than the few one-shots he's been introduced to by another friend. He plays Star Trek Online, so he's getting a kick out of the things that he knows from the games. We are going to stop at the end of DS9, because it's all downhill from there. That other friend that showed the highlights to him agrees.