These one's are sometimes hard to come by, but when I find a series with a strong heroine I'm always super happy. Here are my suggestions (and depending on your genre/cup of tea, I'm sure your interest will vary):
Arang and The Magistrate: Shin Min Ah is a headstrong female lead in this series, and if you like satisfying endings, this one is a really great supernatural/romantic/comedy.
BOSS/BOSS 2: Eriko is the "Boss" of an investigating team. She's one of the two females in this series, but she definitely kicks ass. If you want to watch a really great detective series, with comical elements, this is a really great one.
Dear Sister: There are two sisters in this series, and each of them shares definite strong personalities. This series is so real, beautiful and sentimental. I like that the sisters, regardless of how complicated their lives are, still value each other. There is romance in this one too.
Doctor X (three seasons): Daimon Michiko is definitely one of the strongest females in a series I've ever seen. She doesn't take anyone's shit (literally), among a heavily male dominated medical field. And to make matters better, she's even better than most of them (awesome surgical abilities). This one is a medical-based drama, but it's fast paced, and Michiko is definitely a character to remember.
Flower Boy Ramyun Shop: This drama is so underrated! Eun Bi is one of the most awesome female leads I've ever seen. She comes off as someone meek and willing to conform to societal values about getting a job and going steady, but wow, does she ever change (in barely 2 episodes). One of the most genuine female leads I've ever seen, and the entire series is absolutely hilarious. Definitely not one to miss!
Hi My Sweetheart: Bao Zhu is totally badass, but not annoyingly so. She sticks up for the people closest to her, and rarely does she ever let anyone step over her. There's a really cute but sometimes tragic love story here, but it's a really great series (my bias opinions here, of course)
Hana Yori Dango (Japanese Version): This series has been adapted many times, and even though the Korean one is okay, I find the Japanese one to be one of my favourite versions. Makino is definitely a strong and courageous young woman. A really great series.
Modern Farmer: Yoon Hee is the village head in this series. There's a ton of comedy and hints of romance in this series, so I definitely recommend it for the good laughs and humor. Yoon Hee is a single mom, and she runs the village literally. She's strong and independent physically and emotionally. I liked that she was focused on her work and family.
Sorry if you've watched any of these series and there's overlap! But I would recommend these series for each woman's own unique kickass attitudes and behaviors :)
