I recommend Pinocchio, Healer, W

And also Hwayi and Memories of Murder even though I haven't seen them yet because I only hear good things about those movies
@dearD4NI

These ones are really worth the watch:

Marriage, Not Dating
My Girlfriend is a Gumiho
The Greatest Love
@ViolinGal

Angry Mom
Bad Guys  
Good Doctor
Gu Family Book
Iljimae
Mask
Sassy Go Go
School 2013
White Christmas
God's Gift - 14 Days and Liar Game were both fantastic.
@Kanra

Definitely watch:
Healer
Maou
@Kanra: Healer, it isn't your typical k-drama. Lead actors are great and plot is fast paced (except for couple first episodes which are kind of working as background for the whole drama).
#Edited

@lattebean_

So I meant to reply to Kanra but for some reason my post ended up in the wrong place! So, I'm now replying to you.

Among the top of my favourites list (I love a good historical!)
-Six Flying Dragons
-Empress Ki

Great story/enjoyable (Signal being the one with the stronger plot)
-Signal 
-Beautiful Mind

Good fun
-Oh My Venus

Lucky you. Enjoy! ^^
@fanitha: I already recommended you dramas a few pages back, so I'm not going to do it again, haha.

@lattebean_: I can recommend Uncontrollably Fond and Witch's Romance to you. UF is a beautifully shot melodrama, it's currently airing but I quite like it, I think it's definitely my favorite melodrama. And you need to see WR just for the cuteness that is the main male character and the incredibly good chemistry between the two leads!

@Fortuna:
1. Bad Guys -- my all time favorite drama and the only thing I have rated with a 10, it's super good.
2. Because It's The First Time -- short and fun to watch, especially if you like dramas about friendships.
3. Mirror of the Witch -- an AMAZING historical drama, done quite perfectly, imo. One of my favorite dramas.
4. Ode to Joy -- a very good drama about 5 women's lives and their friendship. The actresses and actors are all really good as well.
5. Somewhere Only We Know -- a movie, but I've seen it twice and loved it both times; it's my favorite asian movie.
6. Teacher's Diary -- another movie, it's shot very very beautifully and is very sweet.
7. The Spring Day of My Life -- you'll love it if you like calm, warming dramas that concentrate on the family part of the plot.
8. Unforgettable -- another movie, but it's very good; also you need to prepare tissues before you watch it.
9. Witch's Romance -- amazing chemistry between the main leads and fun to watch.
Cruel City is dark and gritty with a fast paced, suspenseful story and great characters. I highly recommend it! I can also recommend Liar Game. It is very psychological and interesting. Shin Sung Rok and Lee El are wonderful in it.
@Kanra

This is strange...my post ended up in an unexpected place. I'll just re-post it here where it belongs.

-Limit (really enjoyed it)
-N no Tame Ni 
-The Village: Achiara’s Secret

All great if you like suspense, mystery, and/or psychological elements (which I'm assuming you do, looking at your profile/dramalist ;P).
Yes, I really do! From your PTW, since you seem to be interested in the same:

Bleak Night
Hanzawa Naoki
Cruel City
Boku no Yabai Tsuma
LIFE
@kanra  
healer -> really really interesting love story and very complex character (and good looking hahaha)
sassy go go -> used to be my favourite drama for a long time before i watched comeback mister but this is just perfect i thought this would be a normal school drama at first but for me it had much more hidden messages etc so it was really really good also the process of relationships between characters (not only love but friendship etc) were really nice to watch
@jess:
Bring It On, Ghost -- the ghost part can get kinda creepy, but the relationship between the two leads is very cute and this is fun to watch
Cheese in the Trap -- i saw several people describing this as a dark romantic comedy; it's very good and very realistic, one of my fav dramas
It's Okay That's Love -- another one of my favorites; another quite realistic, physchologically mature drama, they touch a lot of important matters and the actors are all amazing
Lucky Romance -- a super cute drama with a super cute male lead, very fun to watch
The Beauty Inside -- a movie, but as I've said here before, one of my favorites ever, super well done
The Master's Sun -- this is similar to Bring It On, Ghost, but the ghost part is less creepy in this, imo :D very well done and very fun to watch
Uncontrollably Fond -- a really good melodrama, you'll love it if you like beautifully filmed, deep, multi-layered dramas with lots of different stories and problems in them.
@Ineta, you have quite a list of plan to watch :) Among all of them, I'd recommend Reply 1988 because it is definitely one of the best drama and you shouldn't miss it. It might look plain at first but soon you'd be immersed in the story. All the characters are lovely, fun to watch and heart warming. I have an acute withdrawal syndrome after watching it and can't bring myself to watch other drama for a while.
but if you don't have much time and after looking at your list of favorite, I think you'll probably like Pinocchio and Mask 
Ouroboros
Nobunaga concerto