District 9 is a violent and disturbing science fiction thriller. It is also thoughtful and clever, and probably worth seeing if you have a strong stomach.
The premise is that back in 1990 a giant alien spaceship appeared over Johannesburg, South Africa. The ship was disabled and filled with half-staved alien refugees. The government reluctantly took responsibility for resettling them in a refugee camp called District 9, a squalid shantytown that quickly became a crime-ridden hellhole.