This (criminally) under-seen and underrated underwater sci-fi film from James Cameron is perhaps most noticeable for being one of the first Hollywood movies to use CGI. And that CGI scene alone is enough to make it a worthy entry on this list. Even by todays standards, its pretty mind-blowing. The scene in question involves a water-tentacle thats controlled by aliens, trying to make contact with a crew of deep sea drillers. At first, the drillers are frightened, but it soon starts mimicking their faces and expressions, as a sign that its trying to communicate. But then Coffey (Michael Biehn), a Navy Seal, gets paranoid and cuts the water-snake in half with a door, causing it to splash all over the crew. Its a truly fascinating and mind-bending scene, and deserves more credit than its usually given.