I knew I saw District 9 in something else before. Here's the first part of an article at The Last Psychiatrist :
First ten minutes: beginning of Independence Day
Next 30 minutes: CNN footage of Israeli soldiers harassing Palestinians
Next 20: The Fly, when he first starts changing
Next 30: alternating scenes of the beginning of act III of Ironman and the scenes in Escape From New York
Last 20: incomprehensibly pointless- the bad guys (humans) die and the good guys (aliens, of course, represented by a black single father alien-- not a joke) get away.
Credits: future defendants in class action suit
(I'd like to add that the last 20 minutes are the scene from Iron Man, when he returns to Afghanistan to take out the Bad Guys.)