I can't comment too much, as I haven't done a rewatch yet (I still need to purchase it, actually). But one thing I loved about the show was the intro theme, it really put me in the right mood for the show.
I've heard they are using a different theme for the second season, which is kind of a shame, but I suppose shows have to grow and change from time to time.
Maybe it might be a good thing and they are taking the Babylon 5 approach. The various themes represent the attitude of the season as a whole.