I would be ever grateful if you know any! The historical type of kdramas is my preferred genre, but I'm open to modern settings too!

(I know Girls Before Flowers is considered one but I didn't really like Gu Jun Pyu.)

Uhm.. how about http://mydramalist.com/7761-secret  :) (But it's not a historical drama) 
Bridal Mask, maybe. At the beginning the lead male is considered a "bad guy". It's historical drama too. 
Thanks you guys are awesome I will watch them for sure! Also if anyone else has more recommendations please let me know!
Chuno Sageuk drama that has a revenge plot-line and a lead with ambiguous thoughts and intentions.
nice guy
 secret 
they  are kind of  a mixture of bad and good guys 
Empress Ki
Queen Seon Duk