Vampire Diaries is a television show on the CW based on the popular Young Adult horror novels by L.J. Smith. Vampire Diaries is about a popular high school girl, Elena (Nina Dobrey), that is caught in a love triangle between two vampire brothers, Damon (Ian Somerhalder) and Stefan (Paul Wesley).
If it sounds too much like Twilight to you, don't forget the Vampire Diaries books came out first!