The best flamewar?

I never really understood why people are so impressed with Babylon 5

Well, I can't speak for "people", but speaking for myself I was impressed with it for many reasons:

• The image of the future. There's still poverty, there's still war (even between humans), there's still something to envy about your neighbor (money, love, etc, etc), there's still ambitious people motivated by greed, blah, blah blah. It seemed a lot more realistic then TNG or DS9. We also got to see the "common man" a lot more often then we ever did on any Trek series.
• The respect for science and engineering. Actual Newtonian physics. No particle of the week.
• Earthforce is a military force and operates as such. None of this "we aren't a warship" nonsense. Actual respect to real world aspects of the military -- like Sheridan needing to take out a Starfury every now and then to keep his flight pay.
• Likeable characters that grow, change and even (*gasp*) make mistakes that aren't forgotten next week. Name me a Trek character that comes close to Mollari, G'Kar or Garibaldi.

personally thought DS9 was better

They are a lot alike in many ways. Sisko always annoyed the hell out of me though for his whineass speeches, ("I hope it was worth it, I hope to god it was") his assimilation into the role of the Emissary and the fact that we never saw any real consequences for the many times that he disobeyed orders from Starfleet.

That said, I absolutely loved Garak's character, and many previously one-sided characters (Damar, Bashir, and even Quark) grew over the course of the show. I also loved the exploration of some of the darker sides of humanity and the Federation. One of my dreams would be to see such a story with the TNG crew. Maybe an alternate universe movie based around the universe shown in Yesterday's Enterprise. Won't happen, but I can dream.

but I am not going to proclaim it the best sci-fi show ever like I have heard people claim about Bab 5.

I didn't proclaim it as the best ever. It and TNG are my favorites -- for different reasons. DS9 is watchable. The rest of Trek (VOY and Enterprise) are just painful and as far as Lexx/Final Conflict/etc I never really got into them. I watched TNG, Bab 5 and DS9 growing up. Nowadays I don't watch much TV at all. I don't even have cable at home. Better things to do with my time. I'll always remember Bab 5 and TNG (before the movies) though.

I think Bab 5 did a good job doing the build-up to the war with the anti-Vorlons (I forgot their name now), but the final showdown was a big letdown.

That's pretty funny, because I thought DS9 took the cake in the "big letdown" department when they used the prophets to destroy the Dominion fleet. Personally, I would have written that as an extremely dark episode. Think of something along these lines: The space battle goes the same way, but Starfleet has a backup plan in the event that the fleet can't reach DS9 and stop the minefield from coming down. The Defiant is the only ship that makes it through to DS9 and lacking the firepower to stop the station from killing the minefield they resort to plan b.

To save the Federation, Sisko has to destroy the Bajorian son (ala Star Trek Generations), wiping out the Dominion Fleet, destroying the wormhole, but also taking Bajor (billions of people) and DS9 with it. He can do this, or watch the Federation fall within a matter of weeks after the Dominion reinforcements arrive. Then instead of spending the year and a half mostly ignoring the war (they had standalone episodes but largely forgot about it until sweeps week or the end of the season), you'd spend the next year and a half exploring the outcome of this decision. Nothing on this scale has ever happened in the Trek universe (contrasted to the Star Wars universe where they seem to destroy/slag a planet as a matter of course...) and the repercussions would be interesting to see.

Some of the stuff wa

You mean B5's writers were better than Harlan Ellison? WTF? I mean, uh, WTF?????

I was comparing it to modern versions of Trek.

People complain about the original Star Trek's acting, but Ricardo Montalbán, among others (like Joan Collins, who was in the Ellison episode) were in it

Did I complain about the acting on any of the Star Trek's?

TNG's writing wasn't bad either

Really? So this [wikipedia.org], or this [wikipedia.org], or this [wikipedia.org] or this [wikipedia.org], or this [wikipedia.org] were good writing? And I went easy on it -- I didn't pick a single episode from the 1st or 2nd seasons.

Please don't take that the wrong way. I loved TNG. It was my favorite incarnation of Trek and if you look at the 3rd, 4th, 5th or 6th seasons by themselves they are far ahead of most standalone Babylon 5 episodes. But Babylon 5 wasn't about standalone episodes. It was a story. Babylon 5 and TNG are both the shows that I remember. Nothing else before or since has come close.

but the casting was superb

Yes, Patrick Stewart pretty much saved TNG on his own during the first and second seasons, once they started giving him real material to work with. And his character is one of my personal heroes. If we had an actual leader in the real world that was the reclutant warrior with his combination of intellectualism and diplomatic skills we'd be much better off.

I guess the bottom line is that both of them (Babylon 5 and TNG) stood on their own merits. But other then Picard, Data, Worf and (you'll laugh), Q, I'm hard pressed to think of any characters in TNG that grew and changed as much Mollari or G'Kar. None of the TNG characters even came close. And that's a damn shame.