Bride of the Century - nothing good about it to be honest. Just didn't like it.
Doctor Stranger - enjoyed the beginning but it quickly became boring for me, despite having wanted to watch this drama for a while! Would have preferred the male lead to end up with somebody else.
Good Doctor - liked the idea; it was cute. The male lead broke my heart with how he was treated by his colleagues. Despite that, I found it less interesting, the more episodes I watched.
Goong - again, I liked the idea but it was just not for me. It was bad (in my opinion) and very cringy (thinking of one of the female lead's friends). Also hated how annoying the second male lead ended up being.
I Need Romance 3 - watched it for Sung Joon; ended it for Sung Joon. I preferred the supporting couples and hated how the most of the episodes were unnecessary. The story only started making sense at the end, as episode 4-13 (approximately?) literally had nothing to do with the beginning + ending.
Late Night Restaurant - liked it at first but it was just not for me. It's not one of those dramas that I hate though. I had no high expectations either.
Madame Antoine - just... no. I watched it because of its genre (psychological) but I just found it bad. Barely remember why though, other than the male lead being a total douche and the story just being... boring.
Moorim School - "cringeworthy" is the only thing I can think of. The acting was bad and I now understand why I have so little hopes for Lee Hyun Woo's dramas (I had only watched him in "To The Beautiful You" which was years before, when I just started watching dramas, and back then I actually really liked him).
On The Way To The Airport - not bad, just not my taste. I liked the plot in general but the pacing was too slow for me.
Orange Marmalade - watched it while it was airing, dropped it after a few weeks as I fell asleep to one of the episodes, and finished it about a year later.
Personal Taste - it's not super bad if you just want to watch something fairly old and laugh at their ugly sense of fashion. I didn't like it but I didn't hate it either. It was just bad while still being enjoyable... sort of?
Playful Kiss - watched it without subtitles to practice Korean. Wanted to watch it because it was so popular. I still don't understand why a bad drama like that is so popular. Everything about it was bad (it's my friend's favorite drama though, haha). Hated both of the leads.
Scholar Who Walks the Night - good beginning but got boring after a few episodes. Who knows though, maybe it was because I had too high expectations?
Secret Love Affair - wanted to watch something different - loved it at first but I found it too long. I wanted to see the leads loving in secret but instead it was not a "secret love affair" at all?
Stranger - had super high expectations for this, expecting a second "Signal"/"Tunnel" but instead I never had the opportunity to enjoy it. I did not enjoy the first episode but gave it a second chance... and a third chance... and a fourth chance, just hoping that it would get interesting after a number of episodes. I did like the ending though.
Suspicious Partner - still don't get why it's so popular. I enjoyed it during its first weeks. Then suddenly something just happened and everything went downhill.
Sweet Stranger and Me - don't even remember the plot. It was nothing special, really.
The Bride of Habaek - loved the first number of episodes. I felt like it began getting boring as soon as the second leads appeared though, and with my high expectations, getting disappointed was possible. I was hoping for a second "Goblin" of some sort but instead we got something super bad with pretty faces.
The Moon that Embraces the Sun - I actually really enjoyed this... the beginning and the ending, that is. The rest of the episodes bored me. :(
Uncontrollably Fond - barely remember anything from this drama. All I remember is Suzy's acting and her constant complaining.
(It's not even that I hate lots of dramas but at some point you'll just come across some really bad ones or ones that you just can't enjoy, no matter what)