I recommend Flying Colors :D
Mahoro Ekimae Bangaichi
Kill Me, Heal Me!! I've only watched 2 episodes but my god it's so good. (THANKS AGAIN SONGYI!!)
Even though I dropped it, I'd still recommend Who Are You: School 2015.  It was a very good watch for me up until episode 10 and I just couldn't get into it anymore.
Eternal Love - I just finished it, the amound of greatness there! And good effects and story, also the actors.
@Joy
School 2013 is (in my opinion) one of the best school dramas out there! I would recommend it much, much more than the other versions (2015 + 2017). I'm glad they didn't focus on romance but instead on the class (that consists of classmates with different problems). They also focused on bullying quite well.

@EvilYuli
Chicago Typewriter! :)
@momo, I rather did enjoy the 2013 version.  I think it tackled high school problems quite well and I really enjoyed watching the friendship with Kim Woo Bin and Lee Jong-suk unfold.  Also, I really like Jang Na-ra and thought she was really good in this show.
@Sandysan You should really watch Master's sun. First ep or two are a bit scary but the rest are fine and it's pretty funny and entertaining and So Ji Sub's acting in it is 10/10
help me find a drama. 
help me find a drama. 
@Emma: you are absolutely correct!! I thought I loved him in Oh My Venus and then I saw Master's Sun and Oh. My. Goodness! :)
@emma my gf is a gumiho
wolf girl and black prince 
u r beautiful
@joy the liar and his lover 
Nobuta Wo Produce is a classic!
Nine: Nine Times Time Travel