Any Korean dramas with protective, almost jealous and obsessive, male leads towards the female lead? What I'm really looking for is the protective, I-want-to-take-care-of-you element.

Something like Master's Sun - not the Ghost element, but how he always looks out for her.

It's not Korean, but one I liked a lot was Boss and Me.
I've also watched Healer, and Cruel City, and Girl Who Sees Scents.
My Love Eun Dong - very protective and obsessive
Oh My Venus - not that obsessive but he protects her
You've probably seen all of these, but hard time checking your list on my phone:
cruel romance
hotel king
yong pal
i hear your voice
man of honor ( both make characters were obsessed with her)
Thanks. I've watched Hotel King but not the others. I'm adding the rest to my list. Yong Pal and I Hear Your Voice especially. Was My Love Eun Dong especially romantic? The synopsis makes it seem that they spend too much time dancing round each other.
My love eun dong is better than what it sounds. They 'dance round' each other because she doesn't know who he is due to memory loss. Don't want to say much more as it will contain spoilers but its a very sweet love story worth a watch. 
I second My Love Eun Dong & I Hear Your Voice!

I would also recommend FaithCity Hunter (resembles Healer a lot), and My Lovely Girl.
@Nezumi - I'm watching My Lovely Girl right now. I like the romance between the leads and that he wants to take away all her troubles, but I'm on episode two and every time I have an aww moment, I spoil it by remembering he's only this way because he's taking responsibility for his late girlfriends's younger sister. It's like he's an older brother she has a crush on. Will he ever get over himself and her sister and focus on her?
Missing You - There's protectiveness, jealousy and obsessiveness from both the male leads towards the female.
@SSKF oh nice! (I forgot to check your currently watching list so I didn't notice sorry ^^') and yes, he does! so don't worry too much about that :)
@Nezumi - I started watching it just before you posted, so no problem. Thanks for suggesting it. I was going to quit it and then I saw your post so i continued. I like it so far. I'm on ep 6 and it looks like he's weaning off the ex.
Ho-goo's Love (Fool"s Love) - Main character protective beyond belief.  Uee is in the drama and worth watching
Thanks everyone. I watched I Can Hear Your Voice and finished watching My Lovely Girl and it's just what I wanted. I'm off to watch My Love Eun Dong.
I loved the older man / younger woman, the protective dynamic, and the focus on romance and feelings in My Lovely Girl.

I'll tackle the others soon.

Any more suggestions?
Goodbye Mr. Black. It's not yet finished though. The lead is a total protector. :)