same here,

girlfriday just kills me

Sadly it's a trope to have your innocent but honest heroine in kdramas. So there aren't tons of dramas out there that centers on strong women. But a couple off the top of my head are:

Killer Girl K is an excellent show. It's just a 3 part special but it's basically about this girl assassin kicking major ass.

Angry Mom centers around a woman who goes back to school to protect her daughter and gets involved in solving a conspiracy all while protecting her daughter.

God’s Gift – 14 Days, I haven't seen this but seems to be about a mother trying to save her daughter.

Princess' Man has both a strong male and female lead. Sometimes she seems weak but she is incredibly strong especially with the gender restrictions of Joseon.

Mrs. Cop, I've also not seen this but seems to center around a strong woman.

I can't think of any ~genius~ characters in kdramas that are women off the top of my head (and that really is depressing). I can think of a few for jdramas though (Tantei no Tantei features a female detective who hunts down other corrupt detectives, Keizoku 2: Spec features a brilliant female lead) but that's not what you asked lol.

The Princess' Man features two really amazingly strong female leads. I really recommend that show in general. Any Jung Ha Yeon sageuk also has fantastic and nuanced female characters.

I guess we should name Empire of Gold as a smart girl yet again u are right,genius leads is a trend in dramaland for some time now,once a drama pops out it has attached teh word in the description and it's now lost the meaning with all this dramaland filled full of genius,yet again it would be much welcomed a genius heroine but i guess we're asking too much for some reason

I can think of strong/confident, smart female leads but not necessarily classified as geeeeeniuses.

Queen In-hyun's Man
Pinocchio
I Hear Your Voice
King 2 Hearts (maybe the closest as to be classified as genius because she is highly praised for her military skill)
My Girlfriend is a Gumiho
I Am Legend
Runaway Plan B
Delightful Girl Choon Hyang
Arang and the Magistrate
Healer

The best I can come up with are female leads who are geniuses at particular skills. For instance, in Yoo-na's Street, Yoo-na is a genius pickpocket, and in Painter of the Wind, Shin Yoon-bok is a genius painter (though the "heroine's" gender is complicated--it's about a female-bodied male person longing for his/her lost womanhood).

As for dramas with smart/strong female leads...as I've learned from my own struggle over women in kdrama, your safest bet is to find feminist writers and PDs and go through their career.

More "serious" writers: Jung Ha-yeon (most feminist television writer out there, period), Ahn Pan-seok (okay, he's a PD, but his track record is amazing--his collaborations with Jung Sung-joo are most focused on female experience, but his other dramas also feature strong female characters), Noh Hee-kyung (I'd stick with her earlier works like Goodbye Solo and More Beautiful Than a Flower), Song Ji-na (before she sold out--Sandglass and Eyes of Dawn have extremely strong female characters)

More "fun" writers: Park Yeon-seon (if there is a power differential or emotional unavailability involved, her female leads come out on top, for once in kdrama haha), Kim Woon-kyung (known for writing flawed and strong-minded women), Jang Young-cheol/Jung Kyung-soon (they typically write women with...strong personalities, though some (History of the Salaryman) are far more endearing than others (Giant), and they do dabble in the kind of pseudo-feminism rampant in drama--ie, female characters who talk the talk but never walk the walk), Kim Do-woo (though sadly she's gone to pot since What's Up, Fox?)

we cauld add Empress Ki and Queen Seon Deok(Princess Duk Man later Queen SD) as close to being called genius heroines(in this case along strong)

I would add Prosecutor Princess to the list. The female lead played by Kim So-Yeon was described as having a genius IQ, an excellent memory, etc.

Oh my god CYHMH. I like Namjoong Min but his crying in that drama was ridiculous, the faces he pulled made me laugh! I took so many screenshots of his crying face in that drama because I thought they were hilarious. Especially when grandma finds out who he is and he throws a fit about not wanting to go home, bahaha.

And no matter how many things I see Hwang Jung Eum in I will always hear her saying "Maru-oppaaaa" over and over again in my head when I think of her. And that ridiculous bowl cut!

Auw you should watch him in The Girl Who Can See Smells. He was a creepy and sexy villain in there. He almost stole the entire show and overshadowed the lead casts.