BuffyTheVampireSlayer is a popular TV show written and directed by JossWhedon, based off a movie of the same name. The movie was pretty much a flop, but the TV series was quite successful. The series follows the life of Buffy Summers, a teenage girl in Southern California who was chosen by the Powers That Be to fight the forces of Evil. Of course she is given superpowers and a mentor to help her along the way.
The show also spawned one television spinoff, Angel, and a comic book spinoff, Fray. I'm not terribly familiar with Angel (thought he was a boring character to begin with), but Fray is available in trade paperback and is quite good. Fray returns to the Buffy-verse a few centuries from now and tells the tale of the first slayer in centuries.
The show's genius lie not only in the hot girl kicking ass aspect, but also in that the demons are symbolic of the social problems that Buffy faces. In many episodes slaying baddies is secondary to her inner struggles. For an example, <bs> the Master is representative of her inability to find a date for Prom </bs>. There's actually a collection of essays on Buffy and philosophy that I referenced for my Hum 1 research paper. Some of them were very interesting. --RichardGarfinkel