This is just my opinion,
Babylon 5, I feel, was some of the finest caliber sci-fi ever created. I hadn't given the show a chance, always thought the Centauri's haircut was stupid so I misjudged the show one simplistic thoughts like that. One night while Season 3 was new, I caught a rerun at 2:00 am, the episode was A Distant Star; where the EAS Cortez is lost in Hyperspace so they send the Starfuries on a rescue mission. I was really enjoying the episode but when I saw the Shadow ship obliterate the Starfury commander, I was hooked instantly. The following night the then new episode was on so I tuned in, that episode was Severed Dreams, nuff said.
B5's episode arc from Seaon 1-4 were almost flawless, Season 5 had its weak ones but nothing too terrible. The character development was outstanding, the interweaving plot lines that spanned through the seasons were so finely crafted it literally forced me to watch every episode. The Shadows were some of the best villains I've ever seen, puppet masters that instigate wars from behind the scenes. The episode of the death of the Markab race was devastating, the Narn plight moved me as did G'Kar's speeches, anything Vorlon fascinated me, the dramatic fall of the Centauri because of their greed was tragic but fitting. Sleeping in Light was perhaps one of the most moving sci-fi episodes I've ever seen, the final 10 minutes gave me a lump in the throat. I was kinda disappointed Earth went the stereotypical villain route during the Civil War, I wanted to see Omegas and other Earth ships fighting the Shadows, but very little else to complain all in all, I love this show and was on the same track with what little Crusade was allowed to have. I really hope the Lost Tales eventually feature closure to the Excalibur and the Dra'kh war.
I can't stand DS9. That is a million miles from where I began with that show. I love Sisko, really wish he'd been captain someplace else. Love Dax (Mainly Terry but Nicole's fine, her character just wasn't really interesting to me) and O'Brien because he was a TNG alumn. The Defiant was cool, though it always annoyed me how when the protagonists where in there or a Runabout they could take a merciless pounding with little damage while any other cap ships were taken out with 2 shots.
That said, DS9 is the show that made me hate Worf. I liked him in TNG but DS9 ruined the character for me. Odo was back and forth, Quark was mildly entertaining but very annoying, Jake Sisko was useless, and Christ I wanted Rom dead. I tried to get back into the show when the Dominion story began but they ultimately ruined that for me too. I was bored to death with anything involving the prophets and pa'raiths or whatever they were called, and the Founders got on my nerves as much as Weyoun.
There were some episodes that were gems; Sacrifice of Angels, Paradise Lost, Siege of outpost ???, Valiant, that episode where the Romulan Senator is assassinated to convince the Romulans to enter the war and the 'tribbles' episode. But for every 1 episode like those I mentioned, I'd get six of Holodeck mobsters threatening the holographic lounge singer.
God, in one episode they showed the casulties of the Dominion War being posted every Friday, the death count was thousands per week. But in the base at the forefront of the war, the keepers of the only means of the enemy receiving reinforcements, the most strategically important location in the war with so many dying on a daily basis; well have to go play baseball against a ship filled with Vulcans. Man I can't stand DS9.
I've watched all Trek shows, save for Enterprise, and DS9 ranks as the absolute worst for me. But admittedly I'm more interested in the movies of TMP; ST 2 and 6 were just brilliant. From the shows, I liked TNG and Voyager eventually grew on me, their ratio of good shows over bad ones was much higher per capita. But DS9 was the opposite for me.
My two cents for what they're worth.