I absolutely recommend you REC (only the first and second movie tho).
this one is a spanish horror movie which consists of a reporter and her cameraman who went to interview some firefighters and accompany them. They end up in a building and they are trapped there due to the government because apparently there is a cannibal virus inside the building. Something that makes this movie special is that is restricted to being viewed in first person with the camera of the cameraman and it just makes it more realistic and creepy.
I've never met anyone outside the hispanic community and i'm not sure if it's even available in other countries, but trust me if you have the chance to watch it, IT IS HELLA GOOD IT DESERVES MORE RECOGNITION.