Smell of Fear episode question

While reading about the Winchester Mystery House online, I came across a trivia fact on Wikipedia, which says the build team was there to explore and watch "one of the scariest movies of all time". In brackets it says the title of the movie is never revealed.

Before the team watches the video, Kari imitates an iconic scene from the film "Poltergeist", so one could reasonably assume that's the film they're watching. But then Kari says "This is supposed to be the scariest film ever made!". While I agree that Poltergeist is an amazing and scary movie, I can't seem to find any official lists that make that claim.

So is that the film they're watching? Or did they just say that to throw off the audience?