Hotel to Hell

Mention the name Lucio Fulci and one of the very first things that someone will say is The Beyond.  Along with Zombi 2, this is one of Fulci's most famous movies.

The plot of the movie?  I did the lazy thing and looked it up on IMDB:

"The New Yorker Liza Merril inherits an old hotel in Louisiana, and invests her savings to reopen the place. While repairing the building, many people die, and local Dr. John McCabe feels close to Liza and tries to help her to solve the mystery of the hotel. Meanwhile, Emily, a blind woman, advises Liza to leave the place as soon as possible. Later they realize that the place is one gate of hell and has been opened, permitting the dead walk on Earth."

The real fun in the movie isn't just the ways in which the people die, but also the scare factor.  This is definitely not a movie that you would want to try acid on (not that I do that kind of thing) because the movie is pretty weird even without someone trying drugs.  While not nearly as gory as Zombi 2, The Beyond more than holds its own in that regard and has one of the most ambiguous endings that you will see.  In other words, it's up for open interpretation.