8. Evil Dead
The Plot: Archaeologist finds an obviously evil book. He then goes to a cabin in the woods, and reads from said obviously evil book. Demons come out. Later, kids go to said cabin, and find a recording of the archaeologist reading from the book, which summons demons. Everyone gets possessed, except one of them manages to find a way around it, and goes on a crazy awesome journey in the sequels.
The Solution: Don't read from books bound in human skin and inked in human blood. No good can come from it. Also, if you're a professor who finds this book, and you can speak ancient Sumerian, and it says "Don't read from this book," then you're just begging to get possessed. Even worse, why would you make a recording of it? And, assuming you thought the demons were just silly legend, why would you keep that recording around for anyone to play? Why don't you burn it? Along with the book? And, furthermore, why do teenagers know about your cabin? Who is renting out a cabin owned by an archaeologist who brings home books made of human flesh? I would ask more things, but this is the same movie series where a guy fights his own hand. I don't think logic was their primary concern.