Contrary to the poster's tagline, this was not the best (nor was it the last).
The reason I have never really warmed to this one has mostly to do with how mean-spirited it is. I realize that is an odd complaint for a slasher flick, but setting a large chunk of this at a shelter for abused children really sets the film at odds with its quippy villain/jokey tone. Maybe if it had a more serious tone, I'd appreciate it more.
The kills are clever, I suppose, but again, mean spirited since it relies on the fears of abused teenagers. I always feel slightly dirty after watching it.