8. Life - Calvin's Switcheroo
Life is one of those films that often divides audiences as to whether it's actually good or not. Truth is that Life is a fine science-fiction horror movie, adhering to the conventions of the genre whilst referencing other inspirational films of the same ilk in the process, and whilst it might be unremarkable in its central plot for the most part - it really goes balls to the wall with its ending.
After spending the whole damn movie trying to keep some gloopy space creature from snapping every bone in their bodies, the last two survivors of the compromised International Space Station - astronauts David and Miranda - manage to trap the lovingly named extra terrestrial Calvin into an escape pod with David, blasting it into deep space to avoid a Earth-bound catastrophe should he manage to get off the ship. Miranda intends to return to Earth to warn the populace about the killer martian.
Only, when the pod lands in the ocean, Calvin and a screaming David can be seen - whilst a lone Miranda has been condemned to death in deep space. It's a brutal finale, and all but make up for any qualms people have about watching Ryan Reynolds die horribly in space. Might as well throw the whole planet away.