Jirisan! I totally forgot this one until i saw someone mentioned it above.
Rating: hated the drama for being mind bogglingly stupid.

Vagabond, though this one is more suited as “i watched it for the love of beanies” cos the comments and fan wall was so chaotically entertaining (even more than the drama) that i kept going so i could join in the fun.
Rating: Hated the drama, loved the beanie experience.

These had actors I love and were good in the first half-ish, stuck to the end because of the actors only:
Big
Moon Lovers
Something in the Rain
A Piece of Your Mind
Goblin
Bride of the Century
Come and Hug Me
Temperature of Love
She Would Never Know
Do You Like Brahms
Sisyphus
Tomorrow With You
Encounter
When the Weather Is Nice

Bored from the start but kept waiting for the hype to be justified:
Squid Game

Record of Youth
I hated all the positive characters, wished them badly from the beginning to the end of the drama. Only the negative ones looked straightforward, at least they were selfish in an open way, while the "positive" characters were the same, except that they were supposed to be liked. In my opinion, it is one of those dramas after which you feel disgust, aversion to actors and the world of entertainment.

In my beginning of watching kdrama, I had this notion that I had to finish a show I started. That has since long gone but there are some memorable hate-watches I recall.
Sassy Girl Chun-hyang. Everyone said it was sooo good. So somewhere down the absolute mess of miscommunication, it had to get better, right? No. It didn't.
Goong. Why is it so difficult to talk to one another!?
Blood. This, I wanted to like. It was the bizarre ending that did the drama in. That, and the killing of Jung Hae-in.

Ohlala Spouses (2012) - hated it from start to finish, but kept holding out a hope that it would somehow get better....

I'll Find You on a Beautiful Day: So. Boring. With cold and/or irritating and totally unappealing characters. It was the only drama that took me ages to watch until the end.

Oh! I remembered one I did hate-watch in recent years! One Spring Night! That one made my blood boil the whole way through!

Healer. seriously didnt get it... too too many consipiracy parts and many boring actors

Bossum Steal the Fate--I binged this because on another Drama Chat people listed it as "Your Current Top 10". The 1st 10 episodes were fantastic, but the last 10 got so boring and repetitive. I had to fast forward through the a lot of them. I kept waiting for it to get the magic back, but it never did for me. I usually drop dramas if I'm not enjoying them, but I stuck with this one because the 1st half was so good.

I don't think I've ever actively hate-watched any drama until the end, but there are definitely times when I look back at the questionable decisions in my drama-newbie past and ask myself how exactly I made it through K-POP - The Ultimate Audition. (The obvious answer being: I needed a quick replacement for You're Beautiful. Plus, I'm the ultimate sucker for cross-dressing.)

The Heirs. I hated it with the heat of a thousand suns. Still do. Woobie’s somewhat redemptive arch notwithstanding.

A true hate watch indulges the less saintly aspects of our character: We are watching so that we can make nasty comments and find faults or flaws. It is a way of releasing our inner nasty harmlessly. For me this was a show named FOREST.

1. Moon lovers- one of the worst saeguk dramas I watched.
2. My Ajhusshi - too depressing
3. Mary Stayed out all night

@missvictrix thank you so much for putting this topic out there. I keep coming back to read the updates and it has me crying with laughter every time.

I can feel the pain as people describe the reason for their hate watching. This almost made it worth my while hate watching those dramas because I now know that level of frustration hoping it would get better or at least that we would find out the reason for the aspect of the story that we just need to know so we don’t feel we have been left hanging.

Brilliant topic, to unleash these emotions and what a joy to share the moment with so many.🤣

Romance is a bonus book, Melting me softly and Abyss.
Now I have learned to drop and fast forward.

I hated myself for watching MY SECRET ROMANCE to the end. It was so incredibly boring in parts, but Sung-Hoon is such an eye candy.

It has been a long time I hate watch a drama.
I remembered watching ' This life is our first ' 'The Smile has left your Eyes' 'Strong Woman Do Bong Soon' because everyone love them a lot.

It was such an unpleasant feeling for me to complete them cause I did not feel the urge .
It was like chewing a rubber glove, tasteless & boring.

I almost never did this except a few exceptions. I just give up on them when I can't stand them. But here are those few exceptions :
1. Personal Taste
2. Full House
3. Undatables
4. Secret Love (This was the purest form of torture I have subjected myself to and swore off the makjang after that)

There are a few dramas that I watched FOR THE BEAN. But I can't recall a single one right now. But two dramas that I hate watched were:
1. Romance. Oh oh oh. Who doesn't know of my epic love of the Noona romance? I sought this sucker out and it was actually really hard to find. I decided that it was hard to find on purpose. Like maybe everyone involved tried to have it scrubbed from the internet and it took a determined soul to find it.
It.
Was.
Terrible.
I honestly feel like maybe the cast owes me a portion of the salary for my pain and suffering. Like. A.dollar a piece in apology. But I couldn't look away. I'm pretty sure I wrote about my experience as I watched it on my fanwall in case anyone wants to relive my trauma.
And 2. Nice Guy..
No one was nice. Not a single person. I spent the entire time with my hands covering my mouth, shaking my head in horror and blithely clicking the next button thinking it HAS TO GET BETTER IT HAS TO. And it does not. It does not AT ALL. I'm pretty sure every episode begins with, "you thought LAST episode was bad? Hold onto your hat, sister it's getting worse!"
Even the memory of those make me want to upchuck a little bit.

Flower Boy Ramyun Shop: I hated the male lead
Sisyphus: Over the top but naaah
Jirisan: It was boring

umm, so here we go...
1. The King: Eternal Monarch
2. Flower of Evil
(let's not get me started on 'why', I've ranted enough, ha!)

Ooh joining the fun. When I first saw this topic I was like no, I usually drop the dramas I hate but when I dug deep I realized there were a few I sat through:
1. Mirae's Choice - this was waaay back in my drama watching days and I kept hoping SML will choose SFL but no, he insisted. Sigh
2. Lovers of the Red Sky - what in the sorcery is this?
In my defense, I was coming out of the devastating ending of 2521 and I needed to see "fluffy romance with a happy ending". I asked a friend about this and she gave me two dramas. I hated LOTRS with passion but I HAVE to have my happy ending. Which led me to the 2nd drama my friend recommended.....
3. Hometown Cha Cha Cha - the beginning eps were ok but what in the world was that aegyo? Why did she turn 12 after she's in a relationship? I cringed through it till the bitter end and I still wished she had picked Sunbae (Lee Sang Yi). I would :)