What are some of the dramas that you've watched that you can rate 10/10. The only one for me is Cruel City.

There are many dramas that I have rated a 10 despite their imperfections because I ended up loving them anyway. However, the ones that I can say were absolutely perfect are:

1. You're Beautiful

2. Arang and the Magistrate

3. Bridal Mask

4. It's Okay That's Love

5. King of Baking Kim Tak Gu

6. Gu Family Book

7. One Litre of Tears

8. Boss and Me

 Black & White Taiwan 2009
Change! Japan 1998
City Hall South Korea 2009
Conspiracy in the Court South Korea 2007
 Long Goodbye Japan 2014 
May Queen South Korea 2012
Mother Japan 2010
MR. BRAIN Japan 2009
Punch South Korea 2014
Sandglass South Korea 1995
Soredemo, Ikite Yuku Japan 2011
The Kingdom Of The Winds South Korea 2008
What Happens to My Family? South Korea 2014
+
The journey-tumultous times (singapore)

Are any of them perfect,probaby not, but Soredemo, Ikite Yuku comes the closest.
The Princess Man
Innocent man
The dramas I have rated a 10 so far:

The Master's Sun
Scent of a Woman
You Who Came From the Stars
Kill Me, Heal Me
The Greatest Love

And probably when I finish it: The Princess' Man
Dramas I gave a 10 (for the personal impact)
I Hear Your Voice
MR.BRAIN
Kill Me, Heal Me
Nobunaga Concerto
Piece (First time I gave a ten, this drama was a big surpise)
Akagi
Bad Guys
Jewel in the Palace
Karamazov no Kyodai
Queen Seon Dok
White Christmas
Saiko no Rikon (maybe?)

Innocent Love
Taiyou no uta
1 Litre of tears
Secret
1. Misaeng
2. Persevere, Goo Hae-Ra
3. Hidden identity
4. bad guys
5. Aozora no Tamago
6. it's okay, thats love
7. Shut Up: Flower Boy Band
8. bridal mask
9. d-day
10. kill me heal me
I don't know how perfect these might be for some but these are the ones I've rated 10/10 ever since I started watching dramas in 2008. Please consider the fact I was in Junior High 2nd grade back then and now I'm 21 :D

- Hero (Korean one with Lee Jun Ki)
- My Name Is Kim Sam Soon
- My Girl (Japanese one with Aiba Masaki)
- Angry Mom
- Queen Inhyun's Man
- Quartet
- Wonderful Life
- Boku no Ita Jikan
- My Girl (Korean one)
- White Christmas
- Byakuyako
- Can You Hear My Heart
- Chuno - Slave Hunters -
- My Boss My Hero (Japanese one)
- MR. BRAIN
- Don Quixote
- RUNAWAY
- Unfair
- Shoot My Heart (movie)
- Full House Thai
- Gachi Baka
- Missing Noir M
- Ghost (Korean one)
- Time Between Dog & Wolf
- They Kiss Again
- Gokusen 1, 3, movie
- Good Doctor
- Great Teacher Onizuka (90s version)
- Hana Yori Dango Final Movie
- Me Too, Flower
- 14 Sai no Haha
- Ho Gu's Love
- Hong Gil Dong
- Majo no Jouken
- I Hear Your Voice
- Iljimae
- Innocent Love
- Invincible Lee Pyung Kang
- Taiyou to Umi no Kyoushitsu
- Switch Girl 2
- Kagi no Kakatta Heya
- Kamikaze Girls (movie)
- Kill Me Heal Me
- Sunao ni Narenakute
- Kimi wa Petto
- Kingyo Club
- Summer Snow
- Stand Up!!
- Strawberry Night

I recently lowered my ratings for some dramas after the last one I completed... I'm not sure about "perfect" because most of my 10-rated dramas were given that rating for somewhat different reasons, and it's sometimes hard to fairly compare one to another... but so far, this is my "perfect" list:

Nirvana in Fire (c-drama 2015)
Koukou kyoushi 2003 (j-drama 2003)
Gunshi Kanbei (j-drama 2014)
Orange Days (j-drama 2004)
Beethoven Virus (k-drama 2008)
Kimi wa petto (j-drama 2003)

I think by this time next year my list may have changed a bit... because I plan to watch some of the dramas that I've noticed always come high on people's ranking lists. :)
jdrama:
Hana Kimi (the original)
Nobuta Wo Produce 
Sunao ni Narenakute
IS - Otoko Demo Onna Demo Nai Sei 

kdrama:
You Who Came from the Stars 
Faith
Sassy Go Go
nice lists, im seeing some similarities between them so im guessing people have similar tastes. im quite picky when it comes to my shows as i only i have one drama that i rated 10/10 but im hoping for more.
 
k-drama:
cruel city
three days
God's gift 14 days
healer
missing noir m
reply 1997 + reply 1988
that winter the wind blows
ghost

j-drama:
Ouroboros
koinaka
siren

c-drama:
my first chinese drama that i'm currently watching(and loving!) : love me if you dare