I was very dissapointed with the ending in K-Pop Ult. Aud. there were too many loose ends left dangling, which is a shame because otherwise I loved that drama.
Dream high 1 and 2's endings were dissapointing to me as well, although not terrible, they just lacked details. (I would have loved to know who the main girl in DH1 ended up with the "country guy" after all). The plot of DH2 lacked focus IMO, but that's another story.
Goong's ending although it was cute just lacked details, and it's a shame since it was a really fun drama.
Rooftop prince's and Love rain's endings both were a little so so for me unfortunately, but otherwise I loved both dramas.
Silence's ending made me so sad for the girl and guy -I wish he would have told her about the cancer sooner.
Devil Beside You's ending was good, but I really wanted to see them get married.