Let The Right One in
This film's strongest point is also the source of its biggest downfall: Too much time is spent on the relationship storyline between the Main Character and his new "crush" and not enough is paid towards the Objective Storyline. As a result it's hard for an audience to determine exactly when this story will end, thus obfuscating the film's true meaning. That being said, most films leave the relationship part completely, so seeing it here is a welcome find. Bonus points for it being more psychologically-scary than disgusting-scary.