I want to watch a drama where Female Lead is strong and takes revenge on bad people. I don't want to see a Female Lead who falls weak because of love. Female Lead should be strong, intelligent and plans her revenge perfectly.
Are movies also acceptable? If yes, then try Azumi 1 & 2. It is about female assassin who takes revenge against lords who want to start a war. If you like sword fights and a lot of action then you may like it.
Yellow Boots is a great daily drama, the FL starts off nice/naive but she becomes a stronger FL in the later episodes and slowly gains allies to help with her revenge. I'm still watching it myself but I'm addicted to this drama! It's 108 episodes but it's worth watching for anyone who likes makjang dramas. You can watch this on Youtube for better video quality than on Dramacool (it may not be available for all countries so use VPN)