I have on DVD, and have watched all of Babylon 5, Star Trek DS9, Farscape, Firefly, Stargate SG-1, Stargate Atlantis, Battlestar Galactica (Classic and Remake), Buck Rogers, The X-Files, and I've seen all or most of Doctor Who, ST:TNG, ST:Voyager, and a bunch of other scifi shows. Out of all of these, I like Farscape the most, but Babylon 5 is a really slose second. Far more than any other show I've seen, the characters develop, mature and evolve. The whole plot was masterminded by a genius (J. Michael Straczynski, one of my favourite comic book writers), not just thrown together episode by episode to see where it goes. JMS planned out the entire history of his Babylon 5 galaxy in advance, and stuck to his plan, that's why the show changes so much through each season, instead of just staying in the same place forever, (like the Stargate series). In the first season, there isn't much happening yet, but we get to know all the characters and all the pieces are laid out for what happens later on. Then the war begins, and you're in for some of the best space battles ever seen, almost as good as the final Death Star II battle in Return of the Jedi.
Unlike nearly every other show ever made, Babylon 5 hardly has any filler episodes. Every episode is important to the overall story, so if anyone is interested in watching the show, you have to watch every episode and every movie from the start in the correct order. There are websites out there that explain the viewing order, and it's really worth seeing this series if you missed out on it when it was first aired, like I did.