Horror Films ruined by the ending

Were you watching a horror film recently that you thought was really good only to get to the second half or the end and be really disappointed?

This one horror film I saw recently “The Last Broadcast” (1998) which is a found footage/mockumentary horror film about the death of the crew of a fictional local film crew by the supernatural Jersey Devil. When I first watched it I thought it was really good at first but then near the end (Spoilers) it turned the guy narrating the whole time was the killer which kind of ruined the whole mysterious supernatural feel that the movie gave of!

Has anyone ever had this experience? Just had to get this off my chest!