Signal, It's Okay, That's Love and To The Beautiful You are my top 3 favorite dramas ~ ! 
I remember you - 10
Pinocchio - 9.5
W - Two Worlds - 9.5
1. Cruel City-10
2. Fated to Love You Korean-10
3. Beautiful Mind-10
Reply 1988
Signal
Incomplete Life
Healer 
Another Miss Oh
My love from the star 
It's Okay That's Love
Age of Youth
Dear My Friends

I give them straight 10 because they're that good!!
Master's Sun
Signal
It's Okay That's Love
Mine are:
Descendants of The Sun
School 2015
High School - Love On 
They're all 9.5 and rated from most to least loved :P
Kill Me, Heal Me
That Winter, The Wind Blows
You Who Came from the Stars
From most to least:
It's Okay, That's Love
Healer
You Who Came from the Stars
(granted I haven't watched that much drama yet so maybe this'll change, who knows)
Lan ling wang
Love O2O
Iljimae
Hey!! My top 3 would be:

Oh my ghost
Descendants of the Sun
Another Miss Oh

All rated 10 :)
Love O2O
Legend of Lu Zhen
Lan Ling Wang
I sorry I love you
Rooftop prince
All about Eve
Age of Youth
Signal
What Happens to My Family