Monsters (2010)
In this tale of reverse Avatar, where humans accidently bring glowing aliens to Mexico and can't get them to leave; writing, directing and even the visual effects are done by Gareth Edwards. We follow a cynical photographer and some women he may be professionally related to as they try to get back to America through the "Infected Zone". The characters take the danger about as seriously as you would take the film as a whole. Let's just say all involved will be saying "I'm glad that's over!" by the time the credit roll in the unriffed version.
If nothing else, the movie proves even the largest walls can't keep aliens or mexicans from crossing the boarder. It will also not leave you wondering what giant, glowing, CGI alien octupi look like having sex next to the gas pumps at a Texaco station.