Considering only the settings published by TSR and Wizards of the Coast, I would pick Forgotten Realms as the one I actually dislike, for the usual reasons. I consider SpellJammer to be a silly concept and, as such, I never got the trouble of reading it and I don't attach any strong feeling for or against it. I disliked Planescape's jargon, but I enjoyed the setting. I liked most of the others, some more, others less.
Outside TSR/WotC, I dislike the World of Darkness, the new SpaceMaster setting, and the setting revision in Traveller: The New Era.