Kafkaesque and Terrifying
For me, horror that is truly scary comes from what you don't know or see rather than what you do. Cube fulfills this perfectly. What is the Cube? Why is it here? Who would use such a machine? None of these questions get answered, and none of it matters if the next room can kill you. It was also one of the best films we saw in my sci-fi group, and one of my fondest memories will be a riff at the ending as the lone survivor walked into a white light. Mike called out "Do you have any suggestions on how to make the Cube better?" We broke out into laughter; after this film, we needed it.