I liked DISTRICT 9...it's like an inverted INDEPENDENCE DAY crossed with THE INCREDIBLE MR. LIMPET. Seriously.
It's explained that twenty years ago a huge alien ship, a mile across, entered Earth's atmosphere and then hovered over Johannesburg, South Africa. For weeks. Mankind manages to get inside it, to find the aliens weak and malnourished. They are refugees.
Now, the immigrants are all forced to live in a barricaded slum and are referred to as the derogatory term "Prawn", because they look like humanoid shrimps.
Wikus Van De Merwe is a government agent who is given the job to evict the aliens from their homes and relocate them to a new facility miles away from the city. This does not go very well. He's accompanies by armed soldiers and there's fatalities on both sides. They interrupt some alien experiment that is happening and Wikus gets splashed with some type of liquid, which soon starts to transform him into a Prawn. The government finds this out and wants to experiment on him, since he's the only human, ever, who is able to operate the alien weapons. All of their technology is organically based and is keyed to their alien DNA. Wikus does not want to be dissected and so escapes back to the alien slums, where he finds an unlikely friend and comes to a new understanding about the aliens.
This movie operates on several levels. It's a fast-paced action film, a social commentary and a touching drama. And it has some of the best computer animation I've ever seen. Definitely check this movie out. It is not just another "alien movie".