Could someone recommend a historical drama for someone who is new at them? Preferably Korean dramas is what I'm looking for.
I recommend you to watch one of these:


Korean

- Iljimae
- The Princess's Man
- Tamra, The Island


Chinese

- Startling By Each Step
Must watch Iljimae, Warrior Baek Dong Soo, The Bridal Mask, and The Princess Man.
From your list

Empress Ki (airing)
Queen In Hyun's Man
The Moon that Embraces the Sun

And

The Princess' Man
The Legend
Jang Ok Jung

And if you ever want to try a Chinese historical
Startling By Each Step
Jewel in the palace Jumong Queen Seon Duk Ding Yi Dar Jo yeong Ijimae e.t.c
I saw that you've watched a lot of longer dramas, then you might like one of the classical historical dramas like Jumong, Dong Yi, Yi San or Jewel in the Palace. They're usually longer. I haven't had the chance to watch them yet, but I always hear a lot of good comments about them and I really want to watch them sometime in the future.
i recommend Queen In Hyun's Man to start with. It's really good.
The very first historical drama I've watched was Hwang Ji Ni and it was really good too. Although, the plot is different from the other dramas and this is probably the most realistic historical drama I've ever watched.

I recommend these dramas too, but you will enjoy them more if you are familiar with the "historical rules"
Sungkyunkwan Scandal (one of my favorites)
Moon Embraces the Sun
Princess Man
The Princess' Man (was my first sageuk; would recommend to start off since it's shorter and has less politics) Jewel in the Palace/Dae Jang Geum Queen Seon Deok Iljimae Hwang Jin Yi Horse Doctor (although the MDL rating isn't great, I thought it was pretty good; might like it if you like medical stuff) The Moon that Embraces the Sun Jang Ok Jung Sungkyunkwan Scandal Jumong (haven't seen but have heard good things) The following are fantasy but in the same time period: Arang and the Magistrate Gu Family Book Might want to check out Bridal Mask too; although it is not a sageuk (I'm guessing you're looking more for the traditional Korean historical drama), it is still historical and is definitely worth the watch. (:
I think Sungkyunkwan Scandal is the best to start off with. after that you might enjoy Warrior Baek Dong Soo or Illjame. Then something longer like Queen Seon Deok. I don't really consider Gu Family Book or Arang and the Magistrate Historicals because they are mystical... but they are fun to watch. The Legend is also pretty epic. If you want to watch a fun Chinese one I recommend Holy Pearl :D mmm...A Tree with Deep Roots was a really good historical drama. and Hong Gil Dong is great, don't be fooled by the first episode.
If you prefer longer dramas then:

- Dong Yi
- Jewel in the Palace
- Queen Seon Duk

If you pferer something mixed (fantasy)
- Arang and the Magistrate
- Gu Family Book
- Queen In Hyun's Man

If you prefer some movies:
- House of Flying Daggers
- Curse of the Golden Flower
- Masquerade
- Red Cliff 1 and 2
- The Restless

Hwang Jin Yi - was also my first Korean sageuk, so if you prefer smtg "similar" to "Geisha's Memories"... ;)

If you are interested in certain period of Korean history or in regin of certain King, you can look at my little list, which will help you find which dramas are taking place in that time period :)

PS. Happy to see another person who loves historical dramas ^^