Kirk/Keeler was my favorite.
Odo/Kira was good in parts but I could never get over the feeling that they were just thrown together because they were two series regulars. And early on it was just painful...the Odo/Kira/Shakaar triangle. His choosing his love for her over the wholeness of Great Link made the romance astonishing. But Odo and Kira as friends was much more believable for me. His reaction to her at the end of "Necessary Evil" is one of DS9's greatest moments.