We’ve kept most of this list to American-made films, but when it comes to “The Descent” we definitely had to make an exception. This British import surprised us all with just how creep, claustrophobic and unnerving it was. The story centers around a group of women who become trapped in an unmapped cave system after going spelunking. But as if that wasn’t bad enough, the group is slowly picked off by flesh-eating humanoids … and, in some cases, by each other. Truly a girls trip gone very, very wrong.