The only thing I disliked about DS9, was the religious overtones.Meh. TOS should be watched because it's a part of history, but it's harldy the best trek, IMO. If you're already familiar with and liked TNG, than DS9 is perfect for your next watch. It starts during the last season of TNG. Picard is in the first episode. Chief O'Brian is in it. Another big TNG character joins in season 4. It's great.
I liked Enterprise, but it was afflicted by the same thing that slowed down Voyager: the constant push to introduce a new ‘favourite alien villain’ to replace the Klingons.
Once each series pushed past that, they got measurably stronger.