When people use a term like "gender-bent" to describe a character, they're missing out if Utena doesn't figure into the equation somewhere. A princess who would much rather be a prince (so to speak), she uses her fencing skills, her honesty, and the strength of her friendship to protect a mysterious classmate from having her peculiar powers exploited by the ruthless and amoral. It's fascinating to watch great complexity emerge from a character so outwardly simple and straightforward, and by the time you get to the end of the series her emotional odyssey has become yours as well. If that doesn't make her a great anime heroine, nothing does.
12. Sailor Moon: Usagi Tsukino
It's not for how she starts out -- a crybaby with bad grades and furtive dreams of being a hero. It's for how she's given power, grows into it by degrees, and eventually becomes a leader with great capability and courage, setting the tone for a slew of other "magical girl" heroines that have since followed in her wake. And depending on how you're keeping score, she also serves as one of the few female heroines in anime who leads a sentai-style hero's troupe. Not too shabby either way.
And now, a dose of infamy. There's barely anyone in the universe of The Slayers who doesn't know the name "Lina Inverse" and run screaming in the opposite direction when they hear it. No surprise why: her grasping greed, her hot-headed flights of fancy and her utterly undisciplined use of magic combine synergistically to create a character you wouldn't want to spend five minutes in the room with -- but as long as she's on the other side of the screen, you can't wait to see what madness she's going to unleash next. Few characters walk such a fine line between being both insufferable and inexplicably charismatic.
It's been said that a harsh environment either crushes people or forces them to mature that much faster. Maka Albarn is proof of that thesis: between her womanizing, deadbeat dad and the pressures of wielding her partner, Soul, as a living weapon, it's a miracle she hasn't flipped out. But she does more than keep it together: she ups her game and becomes a pillar of strength for both her team and her (increasingly troubled) buddy. The fact she's still able to smile through it all says something by itself.