Drama with strong female lead

I am looking for dramas (preferably K- or J-dramas, but everything is fine), with a strong female lead. It'd be great if it had some action or mystery as well. My favorite dramas are such as 'City Hunter', 'Healer', 'I remember you',  'It's okay, that's love'. 

I have yet to find a drama that has a hero and heroine that are both strong characters, and I don't only mean it as in strong-willed, but that they both have some fighting abilities or such. Usually, if the girl's strong, the guy is weak (Secret Garden), or Vice Versa (Healer). The only exception so far is City Hunter, which is why I really love the drama. 

I've been told Time Between Dog And Wolf is a good drama, but the main girl is an annoying b*tch, so I am hesitant to watch it.

Thanks for recommendations :)

Queen Seon-Deok
Empress K
You may hesitate to watch them if u don't like historical or long dramas .. but I really recommend them.
I also recommend Gu Family Book and Cruel City.

Thanks for all the recommendations, i'll definitely check them out! Most of them are historical dramas, though, ahhh I wished there were more dramas like City Hunter with modern action, haha. I have yet to watch I hear your voice, I'll probably give another historical drama a shot afterwards :)

Maybe you can try this one :

7th Grade Civil Servant : korea, romantic comedy, action drama. The characters are secret service agents in an infiltration mission. The woman is better than the man in many ways. I feel it's a little under-rated. It's funny, don't take it too seriously and you'll enjoy it.

Other recommendations of the moment :

Signal : korea, time-travel police drama. A cop can communicate with another with a 20 years gap through a walkie-talkie. The female lead is strong both in character and strengh in present time. So far, it has become my all-time favourite and it's not even finished.

BRomance : Taïwan, gender-bender romantic comedy. The girl has to live as a boy until she turns 26 because of some soothsayer telling her parents she would die as a girl but not as boy. 100 days before turning 26, she saves the life of an underworld mob boss. (He's not bad, he made his people stop illegal activities.) So there are a few action scenes as well.

Protect The Boss - Her father is a martial arts teacher and she was a gangster in school.
Yankee-kun to Megane Chan

Signal.. you should totally watch this. Super good mystery with a heroine that's smart and strong. I admire her so much. There's no weak main character here. This is not yet finished but it's about to end in a few weeks.

Ghost -with So Ji Sub and Lee Yeon Hee