This is, of course, only my opinion.
But I feel DS9 season 4 is the closest thing to a perfect season STAR TREK ever produced. Only half of one episode, "THE MUSE", didn't work... Onaya, the 'Creativity Vampire' as I like to call her. The Lwaxana/Odo story was nice, because it gave a lot of dimension to Troi and gave Odo some great scenes and dialogue, particularly his reason for 'marrying' her.
"THE WAY OF THE WARRIOR" - possibly the best season premiere of the franchise.
"HIPPOCRATIC OATH" - great Bashir/O'Brien outing, and Worf went through some growing pains here.
"THE VISITOR" - one of the greatest episodes of the franchise. I cry every time to this day.
"INDISCRETION" - great Kira/Dukat episode. He got some incredible scenes, and Sisko and Kasidy got a nice storyline.
"REJOINED" - an excellent love story. Dax was well utilized here.
"STARSHIP DOWN" - superb way of using the cast. Worf got some great lessons in command here.
"LITTLE GREEN MEN" - one of the most fun episodes of the series.
"THE SWORD OF KAHLESS" - a Klingon treasure hunt with Kor. I love how Worf and Kor were not under some influence while they bickered.
"OUR MAN BASHIR" - Bashir as James Bond. With Garak. There is no end to the awesomeness of this one. This episode is ALWAYS an immediate rewatch when it airs.
"HOMEFRONT"/"PARADISE LOST" - great two-parter. We meet Sisko's dad, and we see just how much damage the Dominion can do. Without ever firing a shot.
"CROSSFIRE" - Rene Auberjonois really sold this episode. And the scenes with him and Quark were among the best between them. Also a nice reminder that Bajor IS a big part of DS9.
"RETURN TO GRACE" - Dukat's meatiest episode. He got some real depth here. You really couldn't help but root for him, which makes his eventual turn to the Dominion sting that much more.
"SONS OF MOGH" - one of the best Worf episodes. From his decision to go through with the ritual to what he does in the end, this was a rollercoaster for him.
"BAR ASSOCIATION" - excellent development for Rom, who finally steps out of Quark's shadow. And a nice B story with Worf.
"ACCESSION" - we return to Sisko being Emissary, and it was quite well crafted and executed. Another nice reminder of Bajor.
"RULES OF ENGAGEMENT" - what could have been a typical courtroom drama was actually a really good look into Worf's motivations, and great camera work with the flashback scenes with the crew looking directly INTO the camera.
"HARD TIME" - O'Brien REALLY gets it rough here. Great concept, and superbly acted by Colm Meaney. If you don't root for O'Brien, you have no heart.
"SHATTERED MIRROR" - a fun mirror universe episode, and one of THE best Defiant battle sequences ever done... even more impressive is that it was still pretty heavy model work. Watching her fight while circling around DS9 was a truly beautiful thing to behold.
"THE MUSE" - I already mentioned my piece on this one above.
"FOR THE CAUSE" - a lot of nice twists in this one, it kept you on your toes.
"THE QUICKENING" - an excellent Bashir story, his ego gets dropped a few notches. But it truly shows how decent a human being he really is.
"TO THE DEATH" - one of my favorite episodes, it gives a really close look at Jem'Hadar culture. You DO NOT screw with these guys. And we first meet Weyoun... the best Vorta ever.
"BODY PARTS" - a great Quark episode, all these years of growth hit their peak here. Along with Garak, Worf, and Odo, Quark continues the trend of "Deep Space 9: Outcast Central". And THE most creative way to write in a pregnancy of an actress I've ever seen.
"BROKEN LINK " - a nice way to tie-in what Odo did last year, and a good way to end the season with those last few words.
I am nearly at the season 3 finale on the rewatch with my wife. I cannot tell you how much I am looking forward to rewatching this season, and for her to see it the first time.