I'm debating starting a new series, but obviously B5 is a big commitment.
I'm a big fan of DS9/BSG, but most of my frame of reference is Trek, and some science fiction novels.
Worth it?
Danoz, please allow me to give you a little bit of advice before you start watching, without spoiling the series for you.
The entire five years was mapped out before the first episode aired. Changes happened here and there, but the overall story is there starting with the first few frames of the first episode. Many people complain about the first season being "weak". The season is setting up the rest of the series. Things that happen are referenced in later episodes, sometimes years later.
People change. Please remember the era this was in. Look at Star Trek TNG. At the end of any given episode, nothing has changed. The characters are exactly the same at the end as they are at the beginning. Two or three characters may get a promotion sometime in the 7 years, but for the most part, nothing actually changes. Babylon 5 changed things. The characters change, they grow, they evolve. Comparing how characters are in the beginning of the series with their counterparts at the end is a huge contrast.
No one on Babylon 5 is who they seem, or who you think at first.
The first episode is a pretty darn strong one. It's followed by a few that are weaker. By the time you get to the second disc, well ... all four episodes are brilliant. And even their brilliance doesn't hold a candle to what we get later in the first season, and even that pales next to seasons 3-4.
In other words, it stumbles a bit at the beginning, and then gets better and better and better. It rewards you for paying attention.
Hell, I'll even give a non-spoiler example ... In the second season, one character utters a single word. It's a word we learn late in the first season. If you weren't paying attention, well it doesn't mean anything to you (at that point). If you were, and remember what that word means, shivers will go down your spine.