Still not convinced? Fine. You try loving the one thing your purpose on this earth says you have to kill, and then deal with your vampire boyfriend going ten different kinds of evil on you because you slept with him, gave him a moment of pure bliss the curse on his soul says he cannot have, and then see if you have the sterner stuff to fight the not-so-good fight – for a total of seven. Years.
Buffy may not have been abducted by aliens, or assimilated by Borg, or even know what "DRAIDUS contact" means, but she knows what it takes to be a hero. She knows what it takes to be more than just a pretty face and killer of those that kill. And whatever that is, it’s enough for the number one slot.
http://uk.stars.ign.com/articles/885/885032p5.html