Neytiri, the beautiful Na'vi heroine, is a total alpha female. We first meet her stalking and planning to kill the invading hero. Fortunately, she has a change of heart. Then in some spectacular action, she saves him from a pack of creatures (a cross between wolves and saber-tooth tigers) and manages to beat them off while wearing hardly a stitch on her lovely blue body. Her snarl alone is enough to send some of them scurrying.
Needless to say, the hero is more than intrigued.
I've never written what I would call an alpha female (probably because I myself am a sniveling beta) but I'm tempted to try it now. Neytiri is undoubtedly fierce, but she is also uniquely feminine. The trick to making her work, I think, is making sure the hero is an uber-alpha. He has to be in order to be worthy of her.
Have you seen AVATAR? What did you think?