My all time favorite cult/b-movie (by the purest definition of the words) is DEFINITELY monster high:
This movie is insane. Rapping aliens, hot chicks, a weird scene where people open a mysterious door and a red strobe light goes off while blood is randomly splattered like ketchup and a fat girl sits on a cheesecake (?!), and the entire movie is about a basketball game to save the world. Oh, and there's a life size killer marijuana plant.