Martial Art Villainess But I'm the Strongest! - Wuxia, Ancient Times, Transmigration (MC transmigrates and begins to cultivate so she doesn't die at the hands of her stepmother, MC is very badass and doesn't need the ML to save her at every turn)
The Reason Why Raeliana Ended Up at the Duke's Mansion - Fantasy, Nobles, Transmigration (MC transmigrates and realizes she is fated to die, to avert this ending, MC becomes the Duke's fiancè, complete!)
Miss-not-so-Sidekick - Fantasy, Nobles, Transmigration, Comedy (MC transmigrates into Reverse Harem Novel she like and wants to get close to OriginalMC to experience the story firsthand, complete!)
The Devil/Lady Devil - Fantasy(?), Nobles, Dark (don't want to spoil anything, I like it, but it's not for everyone)
Beast with Flowers - Ancient Times, Transmigration/Reincarnation (MC dies and returns to her actual body in ancient times, she and the feared prince quickly fall in love after a chance encounter, complete!)
The Falcon Princess - Fantasy, Nobles (ostracized princess turns into messenger falcon after dying and assists with war efforts)
Roxana/The Way to Protect the Female Lead's Older Brother - Fantasy, Nobles, Transmigration, Dark (MC belongs to the 'Villain' Family and she is determined to bring them down from the inside, MC is really badass and the art style is immaculate)
I'm All Out of Health/I Have No Health - Fantasy, Nobles, Transmigration (MC transmigrates and knows that her new body is very weak and will die soon, so she gives it her all to become healthy and survive)
I thought I didn't have long to live - Fantasy, Nobles (MC thinks she will die soon and decided that she wants to experience at least one loving relationship before then, the ML's reaction to her flirting, etc. is really cute!)
Positively Yours - Modern (After a one-night stand MC becomes pregnant and decides to keep the child after a lot of consideration, ML is the other participant in the one-night stand, complete!)
These are some of the manhwas I liked and could think of at the top of my head, they're all Romance with female MC!