If you like longer family dramas like Golden Rainbow try Ojakgyo Brothers. It's a good one. And UEE is in both :)
Also, based on the rest of the kdramas you've watched, I would recommend Chuno, A Man's Story, and God's Quiz. (None of those are particularly obscure, I guess, but they're not on your list anywhere).
Two dramas that I enjoyed a lot that are kind of ignored are Once Upon a Time in Saengchori and Flowers for My Life. If you're looking for under the radar kind of stuff, regardless of genre or whatever.