The premise of DS9 was stolen from B5. B5 was pitched to paramount and they passed, then went and made DS9...they really ended up being quite different though.
B5 is one my all time favorite shows I still catch repeats I've seen many times already every once in awhile.
Season 1 was the weakest...and probally had the most filler episodes, but it does set some of the storyline up.
Season 2 is when things start to pick up
3+4 (the best) is when the action really starts to get going, and mostly concludes. The show was planned as a 5 year series...but it was thought it might be canceled after the fourth season so alot of stuff was squeezed in and wrapped up.
Season 5- Because of stuff being squeezed into season4 this season is weaker than the others, both main storylines are already over, and the newer ones are weaker...plus personally I found a couple of the new chars annoying.
There were like 4 B5 Tv movies based on the original series.
One led into a new series, "Crusade" that lasted like half a season...it wasn't as good as orig...but it didn't really get a chance to get going.
There was also the sci-fi channel b5 movie/pilot "legend of the rangers". It went up against some football playoff game that got record ratings...and the movie didn't, so the series didn't get picked up.