I prefer B5 plot over DS9 plot anytime. I voted for B5 Cast because of Andreas Katsulas and Peter Jurasik acting. Their acting alone compensated for the few others bad acting in the series.
Sheridan and Sisko were a close fight but in the end i voted for Sheridan because i am more familiar with him.
The Shadows as the villains were far more interesting. The Dominion were nothing more than run of the mill villains who fought others because they saw them as threats. The Shadows were hardcore Social Darwinist who practiced what they preached. A far more interesting antagonist.