If you made me choose between ST:TNG / DS9 and Babylon 5, I'd probably choose TNG, but while TNG was consistently watchable and Babylon 5 alternated between some of the best sci fi out there and some of the worst, the one consistent element to the show for Babylon 5 was the quality of Christopher Franke's soundtrack, which along with being just great music to begin with, fit the scenes perfectly.  It's the latter element that later Star Trek lost in a big way.