When I hear "drama kiss" I see "I miss you"/ "Missing you" scene. Don't really liked the main actress but this drama was amazing~
no doubt LIE TO ME (Cola kiss was great, and housewarming party unexpected kiss) - chemistry between those two was too real for me :)
next: SECRET GARDEN (few kisses there especially at the last couple episodes but I like the exercise kisses and the dance kiss especially the newlyweds milk foam kiss)  PERSONAL TASTE (game over kiss was good) PROSECUTOR PRINCESS (couple that made me giggle from happiness) HE WHO CAME FROM THE STARS ( 15 sec stare kiss or red carpet one plus other) BOYS OVER FLOWERS (MinHo can kiss in most of the dramas so I enjoyed those kisses in there too) GONG (some pretty kisses there too) I MISS YOU ( some kisses were hot)
by the way for me real kissing is a must, I absolutely hate open eye (doll kiss as I call it) kisses 
Can Love become money, at the end of 16. ep.
Any kiss where the couple kisses like people in an actual relationship is good with me. Anytime there is a stiff, emotionless, lips pressed together, arms dangling at sides kiss I just roll my eyes. I'd rather they leave kisses like that out entirely because it ruins the chemistry for me.

Favorite kisses that come to mind are the Cruel City kiss, all of the kisses in Coffee Prince, and the infamous Cola kiss in Lie to Me.
You who came from the Stars red carpet kiss has got to be my favourite kiss of all time! 

Most other kiss scenes make me cringe, the actors and actresses just look so awkward!
Funny this thread should pop on the main page when I just posted about the kiss from Cruel City on my feed. That is hands down one of THE hottest kisses I've ever seen in a Kdrama! I mean, THAT is how normal people kiss. I wish more Kdramas would just GET IT. 

Everyone loved the Cola Kiss in Lie To Me, but I prefer the ending kiss! Now THAT was another kiss you don't see in dramaland too often, much to my deep disappointment!

Common to both kisses is the fact that the female participant doesn't leave all the work up to the male. She is FULLY engaged !!! The way she kisses him indicates she wants his body just as much as he wants hers. None of this shy, innocent business. I love it! 
Every Kiss scene in Healer! OMG!!!! >////< 
Heirs, say anything about but I liked it. Even tho it was just like many other kisses: the woman (Park Shin Hye) just stands there doing nothing.
Mary stayed out all night, I liked the kiss on the the street, hiding those guys who chased them.
Then there is good kisses at least on Secret Garden, Coffee prince, You who came from the stars (I loved the whole drama so.. The kissing scenes were perfect) and Personal taste (the bed scene).

There is probably even more but I don't remember them right now haha
healer - the second kiss
mary stayed out all night - the kiss when they've been running from the guitar students
coffee prince 
faith - the only kiss, but i like it more for the eye contact afterwards, these two have the best chemistry ever.
Oh My Ghost! has the best kiss scenes. I especially like their last kiss at the final episode, Park Bo Young was so cute. 
The Good Wife - episode 12 ^^ And I'll quote someone in the comments : "The best lift scene in Kdrama history."
I finished Chicago Typewriter last week and damn I had to say this somewhere, the kiss between Yoo Ah In and Im Soo Jung in their past life is so so so good! I still can't get over it lmao that man is not from this world
healer 
another miss oh
IOTL, that beach kisses, oh my.. unforgettable. Oh don't forget the supermarket kiss scene too!
(Even though a lot of people hate this drama).. Playful Kiss has some pretty cute scenes! Besides that one, Weightlifting Fairy Kim Bok Joo also has some adorable scenes; epsecially towards the end.