Not sure if this falls into the horror genre but to me it's a horror because it's an actual true story, about two male lions who ran rampant in Africa together and killed over a 130 people and ate about half of them, but they didn't kill for food they killed for pleasure because they enjoyed it. And they were unnaturally smart/intuitive, way smarter then normal lions no matter what protection they set up they got through them, no matter what traps they set the lions saw through them. The Africans saw them as so horrifying, so bloodthirsty and so frighting that they didn't even see them as lions but demons. They were called the ghosts in the darkness.
And most of the events from the movie happened in real life from the boxcar to the hospital just as it's shown, if you watch the movie you'll see.
I love -Insidious 1, 2, and 3! :D -The Exorcism of Emily Rose -Conjuring 1, and 2. Though none of those written above scared the hell out of me, but they're all pretty good movies. Love the plot and the story.
The one movie I can't really stand is "The Human Centipede" though it's more of a psycho movie. *throws up* lol