How has no one posted about SPLASH SPLASH LOVE? It's an all-time fav of mine. Short but a work of art! If you havent seen it, you havent lived!
Jewel in the Palace..
Hong Gil Dong. Not only is it my all time favourite historical drama, it's also my all time favourite drama period. Humour, heartbreak, action, romance, tragedy, that epic feeling of fighting the good fight for what you believe in, that knowledge that even if you die your legend will live on... It's such a brilliant beautiful drama. It's slightly cheesy, but coming from Japanese and Chinese dramas it doesn't bother me in the slightest. I love it so, so much.

I tend to be a huge fan of historical fans, so some of my other favourites include Iljimae and Bu Bu Jing Xin, with the latter having a slight step up from the former. Those are the three that just make me feel THINGS. Such strong things. Lol.

(Also, a comment above mentioned Splash Splash Love, which I wouldn't exactly count because it's time travel, but watching it was two of the best hours of television I've ever watched, no exaggeration. Just a joy and a pleasure and a privilege. Loved it.)
Idk why but I really liked Hong Gil Dong lol..the other famous historical dramas I couldn't finish or had to force myself to finish watching.
Cant decide between dong yi and empress ki...both is no 1 for me..:)
QUEEN IN HYUN'S MAN!
From this list, I must say I have only watched about half, but "Queen Inhyun's man" is definitely my favorite from those. I don't know if it can be compared that well, because it is also a time travel drama (and it plays a big role, not like in Scarlet Heart f.e.) but what annoys me usually with time in historical dramas are the endless plotting at court that can become rather boring. So Queen InHyun's man is special because even though there is a lot of political plotting, the refreshing romance and bickering in the future take away from all the suffering and pain in the past. It is definitely a MUST WATCH for all lovers of historical drama. The chemistry (and kisses, thehe) between the main couple are no joke. Even though the leading man doesn't strike one as incredibly attractive at first, he really grows on you until you appreciate his charms and incredibly good acting. All in all, I've watched it 4 times already and still love it to pieces. Fantastic story, romance, music, comedy, sadness and happiness all rolled into one!
This forum is giving me stress. I can't choose!

The Princess' Man had won me over to saeguk dramas for life. Beautiful OSTs!
Empress Ki was an enjoyable ride, from beginning to end. Strong female character, too.
Dong Yi is probably my favourite female character so far because she was noble and intelligent.
Six Flying Dragons - aah...it was thought-provoking with action. I loved it.

I love the life lessons embedded in saeguk!
Six Flying Dragons
I haven't any of those yet. Still kinda new to Kdrama. But I'm loving Faith right now, suppose that counts as historical. 
Sungkyunkwan Scandal  becoz of actors n actress .
Fortuna -wrote:

The Princess' Man   had won me over to saeguk dramas for life. Beautiful OSTs!
Empress Ki   was an enjoyable ride, from beginning to end. Strong female character, too.
Dong Yi   is probably my favourite female character so far because she was noble and intelligent.
Six Flying Dragons  - aah...it was thought-provoking with action. I loved it. 

I love the life lessons embedded in saeguk!

 I like ur choices and reasons!
Six Flying Dragons slayed me 
rooftop prince ! but did it really count as a historical since they went to modern times i wonder?
The princess man - well writen plot, great and believable character development from innocence to strong, beautiful cinematography especially the part when the majn female lead protect the male fron arrow. 

Sungkyunkwan scandal is akso fun!
The princess man. The story, events and actors were great. some scenes made me cry. it's one of my best Kdrama.

Iljimae, It's good drama I liked the funny scenes and events were beautiful. 

Hong gil dong it's funny.