I saw pretty much all of DS9 during its original run but I was aged between 8-15 then, and a lot of it went over my head. I liked it but found the Bajorans "boring". Having just finished a rewatch I have to say this is my favourite series of all. It's the deepest show in my opinion, with a very wide range of characters. It's interesting to me that they take Worf and O'brien from TNG and make them really compelling characters. As well as even making antagonists such as Dukat somewhat sympathetic. I think it does the best job of character development as all these characters grow over the course of 7 seasons and events actually have future consequences. The whole show builds to the Dominion war arc which is fantastic. My only complaint was the character of Kai Winn who even now I just do not enjoy in any fashion, I'm not sure if this is intentional or not but I don't find her a compelling antagonist.