I watched all the dramas mentioned in here and more, and mostly agree. My favorites are: 
Immortal Yi SoonShin,    HurJoon,    Damo,    Jewel in the Palace,   Painter of the Wind,    Princess' Man,   Sungkyunkwan Scandal.


1. Dong Yi
2. Sungkyunkwan Scandal
3.The moon that embraces the sun
4. Gu family book

Mine would be (in no particular order I guess):
1. Dae Jang Geum
2. The Painter in the Wind
3. Hwang Jin Yi
4. Sungkyunkwan Scandal
5. Empress Ki
6. The Princess' Man
7. Dong Yi

Some are just iconic, others just have a really special place in my heart (like Painter in the Wind for eg.)
1. Sungkyunkwan Scandal
2. Scholar Who Walks the Night
3. Arang and the Magistrate
4. Faith
5. Gu Family Book
6. Rooftop Prince
7. Inspiring Generation
8. Queen In Hyun's Man
1. Empress Ki - Also still my favorite k-drama since forever
2. Rooftop Prince - Although its not a historical drama, I can't help but put it here, its SO good!
3. Queen In Hyun's Man
4. The King's Face
I love historical dramas :) (best storylines and most beautiful music & costumes in my opinion)

My top 10:

1. Queen Seon Deok
2. Yi San
3. Dong Yi
4. Warrior Baek Dong Soo
5. Sungkyunkwan Scandal
6. Jumong
8. The Bridal Mask
9. The Three Musketeers
10. King's Daughter, Soo Baek Hyang

It's really hard to pick, there are so many wonderful historical dramas out there, I also really loved Empress Ki and Iljimae.