It's a very strong series conceptually, but its budget was insanely low for what it was trying to do. What that means is sometimes you have to squint past some ropey sfx (which improves radically as the series goes on) and the odd dodgy performance and bit of hamfisted writing to get to the core of the show: the story arc, which is excellent, and several character relationships and dynamics, most notably Londo and G'Kar.

The show also has a first season which is all over the place, balancing really crappy episodes like 'Infection' and 'The War Prayer' against excellent mood pieces like 'And the Sky Full of Stars' and big episodes like 'Babylon Squared' and 'Signs and Portents' before everything culminates in the S1 finale, 'Chrysalis'. If you can get that far, usually you're hooked in for good. Season 2 is much, much better and the quality remains very high going into S3. S4 was quite badly rushed and some story elements (in some cases, quite big ones) are thrown out of the way with indecent haste to make way for other stories that the writer wanted to address.

BABYLON 5 was pretty cutting-edge and influential for its development of pre-planned story arc-based storytelling, which has been cited as an influence on shows like BUFFY, ANGEL and LOST (the BATTLESTAR GALACTICA writers never saw it, and as a result is a superb example of the inchorent mess your once-awesome series can degenerate into if you ignore the lessons about forward planning that can be learned from B5). It was also the first space opera to use 100% CGI, and its use and development of CGI over the course of the show's history was also revolutionary, going from simple space shots to massive battle sequences to virtual sets and CG aliens. Impressive stuff.

On the minus side, you do have to endure some over-hype about the series. The series main writer, J. Michael Straczynski (who wrote 92 of the 110 episodes), is an excellent writer but also prone to hyperbole. Contrary to popular belief, BABYLON 5 as it appeared on TV (and as it appears now on DVD) was not the show he set out and pre-planned ahead of time. He had to make huge adjustments and changes to the story on the fly, so whilst that preplanning was nevertheless helpful it wasn't quite the be-all and end-all that it is often made out to be.

He's also still prosecuting the needless rivalry with DS9, which is annoying as B5 and DS9 are both excellent shows, B5 more for the epic vision and DS9 for its solid consistency (B5 has the best episodes out of the two, but it also has the worst).