Voting for episodes in season 4 is more fun for me. I think this is an excellent season - the one where DS9 REALLY took off for me.
The interesting thing is that it's not quite as ambitious as the seasons that follow in that there are far more stand alones. However, most of them are strong enough to make the season come together as a worthwhile whole, I think. Also, the ongoing material that IS there, is great, I think.
The biggest complaint I have is probably that there wasn't more follow up to the great Homefront/Paradise Lost. I think this should have had more repercussions.
To make this a little shorter than what I usually do, I'll just briefly comment on the two episodes I left out:
Shattered Mirror: This is an enjoyable, action-packed episode, I think. However, as I said before, I think the mirror universe should have been put to rest after the first crossover episode in season 2. As the storyline progressed, it just became more and more contrived and hard (even impossible) to swallow for me. The way the resistance manages to get the Defiant's construction drawings is - plain and simple - ridiculous and lets DS9's crew look stupid, I think. And that they'd manage to then actually BUILD such a high-tech ship also seems too much of a stretch.
Still, from an entertainment point of view, this is far from a stinker.
The Muse: I actually don't mind this episode. I find it reasonably entertaining and don't think it's anywhere near DS9's worst episodes. Still, it's pretty pointless, all in all, and I don't really need to see L. Troi on DS9, thank you. However, I find her more palatable here than most of the time on TNG, and I like what Odo is willing to do for her.
As for the other episodes, well, I find they're all at the very least 'good' or very entertaining (e.g. Little Green Men), have something to add in terms of the characters (e.g. Bar Association for Rom though I really wish they could have dropped Leeta - she's SO annyoing!), challenge the status quo (The Way of the Warrior, Homefront/Paradise Lost, For the Cause), or they're simply fantastic (The Visitor which is the real gem here and one of my all-time favorites).
I still really like this season. It's great fun almost all the time, I think.