Vampire knight definitely has just what your looking for. the girls name is yuki, whos in love with a pure blood vampire and also has a best friend named zero, who was turned into a vampire and is damned to degrade down into a monster. Zero struggles to fight to keep her away from kaname and keep her away form himself even though hes totally in love with her, he shows his hateful side to her all the time that makes them fight alot but yuki always trys to work it out because its her "best friend" its very good. i *tried* to make an amv about their love/hate relationship but i chose this as my first amv project and well, kinda failed. but i will show it anyway so u can see some clips of it and maybe take better use from it(i also only used the first 4 episodes form the anime, so theres much better scenes to use from VK and its got a twisted ending

)
-sry i JUST signed up to this site and dont know how to post the actual video so ill give u the link
http://www.youtube.com/watch?v=_Dgi2XoRFk0