IN NO CERTAIN ORDER:
Annabeth Chase- The female lead from the Percy Jackson books. She's smart, and a warrior. She's also the daughter of Athena. Annabeth isn't someone you'd want to make an enemy of.
Hazel Lancaster- The girl who the book's all about. She's truly funny, and she's also got cancer. She's pure brilliant as well. The Fault in Our Stars, by John Green.
Deryn Sharp- A fictional female who played at being a boy so she could fly again, from Scott Westerfield's Leviathan Trilogy. (Don't let my lack of commentary fool you, I just have so many reasons for her to be my favorite, I'm letting her stand alone.) Deryn is made of pure dead brilliance.
Rue- The little girl in the Hunger Games that dies in Katniss's care. She's 12 years old, and she nearly survives the Hunger Games. She was killed by a spear when she was caught in a net on the ground.
Luna Lovegood- Luna Lovegood is the who I'd be if I had to be a character in the Harry Potter series. She's strange, and gullible, and everybody loves to make fun of her. But she's also strong, and smart, and she's confident, even though she hasn't got a lot of friends.