I spent last week and went back and watched all of DS9. It suprised me how overall good the series was; from the get go, it seemed to have a basic flow of plot; an involvement of an array of characters and good backstory with all of them.. even cute stories about completely sideline characters (Morn). DS9 was (IMHO) the best of Trek.
Voyager spoiled that. And I can give one great example of this: The Macquis.
In Voyager, they learned to get along but then it just seemed to be dropped. The Macquis were dissidents early and just beligerent without a lot of detail or soul behind their characters.
In early DS9, even to late, the Macquis were not evil people; they were people who felt the federation betrayed them, who made an effective case; one of the better episodes (IMHO) involved Eddington in his announcement that the Federation was "virtually as bad as the Borg" with their insistance that everyone wanted to join..
DS9 seemed to make the most out of situations, Voyager just killed any real story behind things and went for surface level without giving any characters motivation or reasoning. Hell, in DS9, even the bad guys had a decent story that made you try to understand where they were coming from (The Founders, etc.) who were fleshed out to the point even though you disliked them, the thought of genocide, which was attempted, was appalling.
DS9 breathed life into the characters. Voyager just sucked life out of viewers
Enterprise has been pretty mediocre, but it was never as bad as Voyager; and the fourth season of Enterprise has been fairly good.. not great, but definitely better then most TV, and better then anything Voyager had.
Voyager stripped down and went for the T&A show, which is what hurt Enterprise early on.. instead of storyline.