Just because nobody's asked yet, what's your favorite horror movie? And if it's not a Friday the 13th, which is your favorite Friday the 13th? I think I'd probably go Part VII, because I think it had the best Jason costume (the first done by Kane Hodder!) and the very unusual addition of telekinesis into the story, which I'm sure bothered some people but it definitely made the movie stand out from the rest of the series. It was almost like a superhero fighting Jason, which combines everything I love into one movie.
Outside the series, I think the first movie that comes to mind was an interesting horror film called Creep from 2004, about a woman accidentally locked inside the London subway system overnight. It was really well done, and combined a creepy atmosphere with a cool "forgotten evil" concept.
If I haven't heard of your favorites, I'd love to check them out, so also share any horror movies you think people may not have seen, and are worth a watch!