I can't stand DS9. It's much too melodramatic for me, and they overamped things that I consider negatives in Trek.
TNG is my favorite series because it has the most likeable characters, the most balanced style writing, and its top of the line episodes are amazing!
TOS was too "secret angenty" for me, with Kirk holding a phaser on one hand, and a beautiful alien woman on the other. That seemed to be the basic formula for him.
Voyager is TNG lite. I wish the budget they had post Season 4 was seen in TNG instead.