I think season 7 among the worst season of DS9. Demon possessed Gul Dukat was way to much a BAD idea.
http://www.youtube.com/watch?v=XUGxisKfkH4&feature=related
When Jake and Kira had battling energy beams coming out of their chests: lame!! "Evil" energy beings would qualify for the "weak writing" thread elsewhere. Especially since pagh (sp?) wraiths hadn't been mentioned before and come out of nowhere. Like Dukat's mentioning he had an affair with Kira's mom. Like he wouldn't have mentioned that sometime in the previous five years. Ouch. And those are both from season six, I think.