On my stats page, "Strong Female Lead" is the most frequent tag, 140 times :)
Here are some of my top recs
Goodbye to Goodbye - The real leads are the two central women, both are strong and determined, and the younger is the driving force in her OTP, too.
Avengers Social Club - minimal romance, but more strong female leads than you could shake a stick at.
In Time With You - pretty much the perfect example of an alpha female/beta male otp
Nobunaga Concerto - Shibasaki Kou is WOW!
Also, another plug for Dae Jang Geum. Even though it's tediously overlong, and the middle 6 million episodes are cookery classes filmed in what feels like real time, the fact that's based on an actual historical woman (whose name is the ACTUAL name of the Drama) who achieved greatness by dint of her own intelligence and hard work is worthy of note