Yeah, just back to this for a sec. The thing that Halloween, Peeping Tom, Black Christmas and even Jaws do with the the first person thing, is to use it to create a very unusual kind of dramatic tension.
Kal El is right -- first-person is used to gruesome effect in Peeping Tom. That's a classic example, and I think it's the first use of POV in a popular horror film. But there are examples from other genres that pre-date it.
It's not just that it's first person perspective. It's that we the audience know something that the protagonist doesn't (that they're being watched), and the reason we know is because we are viewing them though the eyes of the antagonist.
I'm relatively sure Peeping Tom did it first, but even if it predates that, it certainly isn't the same as simply using the camera to portray a first person perspective, which must surely be one of the earliest techniques going.