This should be obvious to someone who's spent anytime at all lost in the world of "Buffy the Vampire Slayer" or "The Vampire Diaries," but to off a vampire, one needs a wooden stake driven straight through his heart. Vinegar Garlic, holy water, crosses all will not affect your fangs; in fact they just make you mad.
And then there is sunlight. Good old Vitamin D, a vampire's worst enemy. Naturally, how to kill a vampire is different in each show, naturally.