In no particular order my favourites are:
"A Vampire in Brooklyn" (Eddie Murphy, 1995) -- both funny and scary.
"Blood for Dracula" (a.k.a. Andy Warhol's Dracula, 1974) -- ridiculously campy.
"Love at First Bite" (George Hamilton, 1979) -- very funny!
"Count Dracula" (Louis Jourdan, BBC miniseries, 1977) -- brilliant scary vampire flick!
"The Lost Boys" (1987) -- campy.
"Buffy the Vampire Slayer" (TV series) -- great combination of humour, fright & teen angst -- I could see myself and some of my friends in a lot of the supporting roles.
I haven't see either "Let the Right One In" or "Black Sheep" but I'm going to. Especially "Black Sheep," it looks like a must see.