Dude. This is a subject I love. LOVE. Because I can't stand wimpy, helpless female characters who would die if not for their love interest saving them (Bella Swan, anyone?). In fact, I so dislike Bella, I wrote my main character to be the Anit-Bella. (Okay, in all fairness, my MC is saved once by a male character.)
Here is a list of my Anti-Bella's qualities:
1. She stands up for herself.
2. She doesn't need a male character to save her every five pages because she can do it herself.
3. No whining in spite of unfavorable circumstances.
4. She's not afraid to throw a punch.
5. Accepts and faces her fate even when she doesn't want to.
Did you guys know that Ripley from Aliens was written as a male MC? They did NOTHING to change it when Sigourney Weaver played the part. Ripley is AWESOME.
Katniss anyone? She's brave, traded places with her little sister even though she'd be faced with certain death, compassionate, and knows how to use a bow. And she kicks butt, yet maintains all of her female allure.
Eowyn from LOTR. She is beautiful, elegant, and can wield a sword like a man. Not only that, she dresses up as a man and risks her life to go fight the bad guy.
Judith Mercado has some interesting things to say about the female hero. Also, Carolyn Kaufman posted this article about female protagonists, which is far and beyond anything I could write.
What makes your female hero a hero? And what female heros do you love? Hate? And why?