I don't like re-watching dramas but I have re-watched ... You're Beautiful - 4 times Secret Garden - 2 times 49 Days - 2 times Can You Hear My Heart? - 2 times
I can't remember all my rewatches, but I've seen HK Japan 4 times, HK Taiwan 2 times, Gokusen 4 times, Queen In Hyun's Man 3 times, Reply 1997 3 times, among others.
What's HK Japan and HK Taiwan?
dorama911 wrote: What's HK Japan and HK Taiwan?


Hana Kimi. Sorry, I usually abbreviate it.
Up until this week the only show I ever rewatched was you're beautiful (I normally hate rewatching since I have about 200 shows I want to watch) but for some reason this week I was in a mood to watch some of my favs. So I watched city hunter a second time and followed that up with faith and now I'm rewatching you're beautiful for a third time ... next I think I'm going to rewatch shut up flower boy band and personal taste :)
A lot. I tend to rewatch my favorites many times.

Ningen Shikkaku 4x
Ikebukuro West Gate Park 4x 
Life 4x
Nobuta wo Produce 4x
You're Beautiful 2x
Last Friends 2x
Densha Otoko 2x

And I want to watch IWGP, Ningen Shikkaku, 49 Days, and YWCFTS again.
I've only rewatched two dramas: Tree With Deep Roots (twice), and White Christmas (three or four times?). White Christmas just gets better each time I watch it. Funnily, because I actually like Tree With Deep Roots better, but still would rather rewatch White Christmas instead XD
A Lot. too many drama taht I will watch it over and over again.
but still i will give my answer

1. Goong
2 BBF
3. Wonderful Life
4 Sassy Girl Chun Hyang
5. Just You
6. Autumn Concerto
7 the moon that embrace the sun
8 itazura na kiss (1996)
9 Two Weeks
10. Boss n Me
11 You are my sunshine
Liar Game S1, S2, and all movies
Umi no Ue no Shinryoujo
Love Shuffle
Boku to Star no 99 Nichi
Dinner
Bitter Blood
Sennyuu Tantei Tokage
Galileo 1, 2, and all but the first movie
Dias Police: Ihou Keisatsu

And I can foresee full rewatches of Nobuta wo Produce, Lady Girls, and a handful of others in my future. :)
Hana yori dango season 1&2 - 4 times
Nodame cantabile - 3 times
Hana yori dango movie - 2 times
Maou - 2 times
1 litre of tears - 2 times (even though is so sad it makes you want to keep going)
Healer - 2 times
Kill me heal me - 2 times
The greatest love - 2 times
Goong - 2 times
Mars (twdrama) - 2 times
Liar game season 1&2 (jdrama) - 2 times
The moon that embraces the sun
- 2 times
I'm sorry I love you - 2 times
Pride - 2 times
Buzzer Beat - 2 times
Gokusen1
Densha Otoko
Tumbling
Buzzer Beat
Asuko March
Gakko ja Oshierarenai
kazoku game
hana yori dango 1&2
hana kimi
School 2015
Faith, 4 times (i think)
You're Beautiful, twice
Secret Garden, once
Healer, once
Liar game S1 & 2
Hana kimi
secret garden
10/10

I Hear Your Voice => I had to share it with some other people, right ?
Pinocchio => I just love hidden identity dramas
You Who Came from the Stars
Who Are You (2013)
The Painter of the Wind => Most beautiful period drama
Guilty Akuma to Keiyakushita Onna => best revenge
Queen Seon Deok => best period drama
Sungkyunkwan Scandal => the funniest
My Girl
Lie to Me
Signal => I'm even translating it for my friend and family to see.

9,5/10

Kill Me, Heal Me => I shouldn't have watch it more than once. No surprise, no fun for this one.
Hong Gil Dong

9/10

Bridal Mask
City Hunter
Iljimae
Ma Boy => well, only 3 ep. is easy to rewatch
Delightful Girl Choon Hyang
My Bratty Princess
You're All surrounded

8/10

I remember You
Faith
Romance (MBC) => I grew fond of the first 5 ep.. I love the taboo romance.
Myung Wol The Spy => As I said, I love hidden identity dramas ^^
7th Grade Civil Servant
You're Beautiful => even if it's not worth a 10, I still very much enjoy gender-bender dramas.

I'm sure there are others (gender-benders mainly) but... I can't remember them all.