One of my most favorite kdramas of all time would be Manhole. This drama is considered one of the first kdramas I've watched since I only started watching kdramas last year. This drama has everything from comedy to romance to suspense, action, and somewhat of an adventure.
Another one of my most favorite kdramas is Fight My Way. Since you've watched Kill Me, Heal Me, you should know Seo Joon, or at least how he looks like. This drama shows that the main couple as tsunderes (people who seem like they don't care and say things they don't mean but they actually care a lot) and it's really too cute to handle.
I definitely need to mention I am not a Robot because this drama is the definition of robot-human relationships. The story is so sweet and the acting is awesome. I mean I can never act as a robot and another person at the same time. I thank the main leads for all their hard work! <3
I can't believe you haven't watched Blood! It's sci-fi and the male lead is cold-hearted and dense while the female lead is more fierce and straight-forward.
You should also watch Oh My Ghostess. As you can tell, this drama includes spiritual stuff. This is definitely for you if you're in for a comedy!
Oh My Venus is hilarious and it's the type of drama with secret identities. If you're an E.L.F (Super Junior) then you would definitely find this drama funny with Henry in it.
If you're a fan of medical dramas then watch Doctor Stranger. It's a drama that takes you on an INTENSE emotional rollercoaster. It's tragic but the romance it deep and Jong Suk has a really cute hairstyle in this one.