Ok, here I am, my first post on the forum and i'm already talking about sex. naughty, naughty me! ;)
Before you start thinking that I want some good old asian porn, stop there. I'm not looking for explicit scenes and in-your-face nudity, i would simply love to watch a drama where the erotic tension gets settled for once!
Believe me, i love the romance in dramas, and most of the time i'm fine if they just kiss, but the italian in me, needs some action for once in a while XD
E.G: I've watched Last Cinderella, and listening to them talking about their needs was sooo refreshing!
I won't be fooled into thinking that K;J(etc) couples don't have a sexual life; so come on! bring them to me! :D
I was just thinking about this topic the other day! What dramas I have seen where more is shown or implied. There are only a few that I know of, since it appears to be a cultural thing or something. Here are the ones I can think of:

Last Cinderella
Bad Love
Time Between Dog and Wolf
Personal Taste
Queen In Hyun's Man
Fated To Love You (Korea and Taiwan versions)
Miss Ripley
Dandelion Love
Easy Fortune Happy Life
Boss and Me
Akumu Chan (Very subtly implied)
Tempest
Greatest Marriage
She Was Pretty

Healer

Fated to Love You (I've only seen the Taiwanese version, so I don't know if the same can be said for the Korean version)

It Started with a Kiss & They Kiss Again- it's the Taiwanese version of Itazura Na Kiss, the first part doesn't resolve much of the sexual tension, but the second season is filled with kissing.

Devil Beside You

Coffee Prince

There are others, but these are the ones that I've seen that build up the tension that leads to a good payoff.
the only dramas i can think about now are it's okay that's love and i need romance.
alice in wonder city and miss ripley
My rosy life 
Miss Ripley
It's okay that's love
Temptation of Wife

A lot of older J-dramas.
Hirugao
Cruel City - though the tension seemed to build more afterwards
Empress Ki - but it's 51 episodes long for a handful of moments that you're looking for.
King2Hearts
Miss Korea
Miss Ripley
Oh My Ghost
Secret Garden
The Time We Were Not In Love
Hessa Volunteer Staff
It's okay that's love
Shitsuren Chocolatier
Coffee Prince
Personal Taste
Thanks, everyone! <3 <3
A Million Stars Falling From the Sky
The Return of Iljimae
Secret Love Affair
Giant