Here's my take on the DS9 couples:
First of all, Star Trek has never been good in describing relationships. In TOS they wer almost non-existent and in the "Berman-era" series, different relationships often felt forced and artificial. However, I must say that DS9 was the series which handled relationships better than TNG and VOY.
As for the DS9 couples, I find none of them totally hopeless, offensive or unrealistic in any way. They were either good, or at least acceptable.
Worf and Dax feels like the most forced one. No real chemistry actually, just something the came up with because "there had to be a relationship among the main characters". Still, it never annoyed me and sometimes I found it quite OK.
Something similar with
Bashir and Ezri actually. But I still think that one worked better.
Rom and Leeta was the typical "The Beauty and the beast" or whatever. Maybe it worked because it did seem so unrealistic. A beauty like Leeta falling for that little stupid Ferengi. Maybe that's why it actually worked.
Dukat and Winn. Even if I never was that fond of the whole Pah-Wraith thing and even if I found Dukat more interesting as a cardassian in charge, I do have a weak spot for the "nasty couple team up" thing. Not as good as the Culluh-Seska pair of VOY but still interesting and mean.
Odo and Kira. It was nice and sometimes I wish that Odo had stayed on the station with Kira, Oh well, maybe he returned after being tired of splashing around in The Great Link.
Sisko and Casidy. I actually felt bad for those two when the Prophets started to harass Sisko that he shouldn't marry Casidy. What gave them the right to do so?
Anyway, I never liked the end of the series when Sisko decided to stay with those Prophets. I hope that he returned to the station, continued to be Commander and that he moved in with Casidy in that house they planned to build on Bajor.
Quark and Grilka. Well, it couldn't last but it was actually OK and fun when it did.
Miles and Keiko. Actually a nice and normal couple. OK, Keiko could be a bit annoying sometimes but it was pretty much like a normal relationship between aman and his wife.
Garak and Ziyal. Oh I wish that Ziyal hadn't been killed off. I feel so sorry for Garak.
