Buffy the Vampire Slayer was more than mere entertainment. The series of shows put a whole new lexicon into the mouths of teenagers everywhere. Some of my favorites are: cuddle-monkey, geeker-joy and maxi-wig.
If you are super into the linguistics of slayer slang and want to really get into the subject, I suggest you look into this book:
Slayer Slang, A Buffy the Vampire Slayer Lexicon by Michael Adams. You can read more about it in this article done by PBS.