They start brilliant and untill episode 9 I'm hooked. Then the dragging starts and I get bored, but force myself to continue to watch. Episode 13/14 everything gets revealed....mushy romance in the final episodes = snooze.

A good example is Healer. EXCELLENT untill episode 14. But once Chae Young Shin discovers who Healer is and the romance starts...i'm just unaible to continue. I tried watching episode 15, but I just can't concentrate anymore. Which is sad, cuz now I'm unaible to see the conclusion.

Another example: Kill Me Heal Me. Again excellent and I managed untill episode 19. But 20...with that annoying Mr X is such a pain to watch. I've tried to watch it 4 times, but I keep falling asleep.

Anyway I noticed I have this problem with a lot of dramas: BOF, You're Beautiful, Prime Minister & I, You Who Came From The Stars...I also don't feel like watching the final episodes of She Was Pretty...cuz Seong Jun now knows Kim Hye Jin was his childhood friend. So after episode 11 it gets boring to watch. 

There's so far only 2 dramas I was aible to watch from start to finish: Let's Eat season 1, and Heartless City.

Maybe it's the romance + dragging? Anyway Korean dramas are always short: either 16/20/24 episodes...is it really too much to expect the few episodes to keep us engaged? 

Feeling frustrated....

I know what you mean. I just dropped She Was Pretty and really struggled with finishing Second Twenty - which I really loved dearly at the start! T_T

I really prefer those romances which take time to be resolved - maybe that's why I have an preference to noona-romances: they have their age seperating them = real problem. For example, I Hear Your Voice as amazing. There's a mismatched couple and even a serial killer to keep the viewers on their toes. Excellent. I can rewatch it and never get bored.
From your plan to watch list you have some great one that you can watch: Secret Garden, Coffee Prince, City Hunter, My name is Kim San Soon and Autumn's Concert. You can try to watch "Save the last dance for me". These dramas have very strong females characters. I think you might be able to enjoy them until the very end. 
I've also dropped She was beautiful...for now. I dropped a few weeks ago. But I understand what you mean. The apex of the love story kind of ruins the drama when they drama has got little to offer after that, and you still have to watch 4 episodes until the end.

I generally find K-dramas drag near the end, even with the 16 episode series. It's frankly why I prefer J-dramas. The shorter episode count means little-to-no filler needed.
I'm stuck at the 15th episode of Healer and the 12th episode of She Was Pretty, actually - exactly where you said they become boring. I get what you mean, ahahah
ya me too..i think the last two or three eps are just fillers to end the story thats why I never complete dramas it was the same with kmhm and the time we were in love 
If you don't want a drama being so boring after a few episodes, watch The Princess' Man :) Highly recommended! hehe ~
Thanks everyone! I do really need to update my list! But I haven't watched I Hear Your Voice, Secret Garden, Coffee Prince, City Hunter and Autumn's Concerto and Priness Man yet. So will definitely try those. 

Regarding J-dramas...they are great, but somehow they usually make me depressed. K-dramas are more colourful. So I'm not sure whether I will ever completely drop K-dramas for J-dramas.....
You said you dont watch that much jdrama but i strongly recommend Love Shuffle.Its not depressing at all and there are a lot of possible OTP that i think you wont be bored.
I feel your pain, which is why when I hit a drama-slump I opt for C-or J-dramas. Even if they have series that are longer, I feel that they are better at making shorter episodes with less fuller! Of course, taking out the romance element completely gets rid of any annoying relationship drama/misunderstandings that makes the series feel like its dragging. Maybe mysteries or crime dramas are more your thing? I know that after I watched Heartless City (10/10!) I went on a crime-drama binge hoping to find something similar to fill the void. Never did:-(
I know what you mean... Well, I'm not sure about which drama to recommend to you, even my favorites sometimes have a draggy part, but I personally love It's Okay, That's Love, and from my point of view it doesn't get draggy at all... I would recommend 49 Days, Two Weeks, Secret and God's Gift too, maybe God's Gift's beginning is a little boring, but it's a really good drama... 
You should watch liar game Korean version. Only 10 or so episodes and hardly any filler material with acting that is on point from beginning to end.
Yesssss thank you. I feel this so much. It's so frustrating how they start out so mysterious, with so much tension, but then half-way through all the magic is lost. It's really confusing to me, as there often are really good actors, quite good story line, amazing chemestry, and you really care about the characters.. when everything is working so well in the beginning, what are they doing to make it so bland and dragging the last episodes?

sounds like you have the same problem I do. thats why my on-hold list is so long. The most engaging dramas i've seen where I didn't ever want it to end and binge watched every episode for 3 days straight was Empress Ki, master's sun, and jewel in the palace. maybe its because after watching these,  other dramas seem a little lacking and after about the 9th episode I start getting bored. empress ki made me have some ridiculously high standards. 
I totally get you, that's why I mostly watch historicals, because most of them don't get boring till the last episode :)