District 9 is easily one of my favorite Sci Fi movies. It takes this concept of aliens coming to our planet and spins the normal tacky invasion, end of the world scenario we are accustomed to seeing into something much more real. The concept of the aliens arriving not with a plan or course of action, but broken and crippled is so original and thought provoking. considering the movie never explains the circumstances of their condition trying to come up with theories in my head is a very satisfying (I generally find it boring when all aspects of are story are just laid out on a table for you. No fun in that). And that is only the smallest fraction of what makes this movie so interesting. It completely changes the usual idea of the human reaction to alien life. Instead of being threatened, or in a position of being inferior, humans are placed in control of these aliens that are essentially stranded on our planet. The only plot whole I see here is that the aliens show so little resistance to the the negligent nature of our care considering their more advanced tech and weaponry but, perhaps in the same way their minds seem to degenerate as they live in these slums on our planet they forget how to use their tech besides the intelligent few like Christopher Johnson and his son. Once more this is an other area to fill in the gaps with your own ideas since its not really a story breaking element but an area where you can decide to make sense of what has happened. I hope future writers take example from stories like this. Sometimes the best thing is to allow the viewer to become the writer themselves.