Damn, a lot of the ones listed are episodes I like a lot (
"Afterimage", "Take Me Out to the Holosuites", "His Way", "Re-Joined", "The Emperor's New Cloak"). And two of those are in my top ten favourites!

Seriously, people?

Out of seven seasons that each have a ton of stinkers, you pick THOSE as the worst? Methinks some people are spoiled.

Here are my choices (keep in mind that I haven't seen every episode of seasons 6 and 7):
Season 1
"In the Hands of Prophets" - It's hard to pick a worst season 1 episode because I hate so much of that season, but this seems as good a choice as any because I remember that after I saw it, I seriously considered giving up on watching DS9 altogether. I generally hate episodes about Bajorans, and after this one it was many, many months before I finally decided to give the series another chance and started watching season 2, which finally got me into the show for good with the brilliant
"Whispers".
Season 2
"Rivals" - What a waste of Chris Sarandon!

This is one of the many season 2 episodes in which I was so bored I had to turn away from the TV and surf the Internet periodically to keep myself from going crazy with boredom.
Season 3
"Meridian" - Damn close to a character assassination. The way she behaved in this episode was depressingly stupid. The absolute lowest point for my favourite character. I wish I could erase this episode from existence.
Season 4
"The Muse" - I think I would hate this episode no matter what my creative impulses were just because it has such an idiotic premise that is so laughably executed, but I find it especially insulting and pathetic since I have a lot of experience, knowledge, and interest related to writing.
Season 5
"Let He Is Without Sin..." - Worf and Jadzia going to Risa sounds like such a can't miss premise. I would have loved to see this just being about Jadzia teaching Worf how to lighten up so that by the end he's having fun and learning to appreciate her for helping him lighten up. Alas, instead of a good relationship building episode for them, it turns into a boring
'religious fanatics are bad!' story.
Worf annoyed the hell out of me in this episode. First with his refusing to change out of his uniform, then with his actually buying into the cult's crap. I expect Worf to be smarter than that. At least there were some funny scenes with his jealousy of Jadzia and his clueless outrage at Bashir and Leeta, but the bad far outweighed the good.
Season 6
"Sons and Daughters" - Very disappointing last major appearance of Alexander (his presence in
"You Are Cordially Invited..." wasn't much more than a cameo). The Ziyal stuff was a little better, but Alexander's arc in this episode is so depressing and irritating that it makes me never want to see the episode ever again.
Season 7
"Prodigal Daughter" - I think Ezri is a great character, so I was really surprised how dull an attempt to flesh out her character with some back story and insight into her family ended up being. It makes me think maybe I should be glad the show didn't try to do the same with Jadzia. I really couldn't get interested in her family's problems and O'Brien's subplot seemed hilariously inept in how awkwardly it was thrown in.