Vampire Knight: In a bid to broker peace between vampires and humans, there is the Cross Academy. The Day Class consists of normal human kids, but when the sun sets, the Night Class, the vampires take over. Yuuki and Zero are two kids who are guardians with the job of keeping the Day Class from mixing with the Night Class and learning that they are vampires.
I know it has a decent size fanbase, but the problem for me, it reminds me too much of Twilight. The Night Class just reminds me of the Cullens, Yuuki and her vampire love interest of Bella and Edward, and Zero has Jacob. And for a vampire anime, it has very few action scenes, but it is an anime meant for girls with all the pretty boys and the revolving around the love triangle.