I'm a fan of DISTRICT 9. Perhaps mostly because the backstory of the production was a bit of a Cinderella story--little indie guy hooks up with movie mogul Peter Jackson and they change the movie industry and everyone gets rich and live happily ever after. Well, not exactly, but you get the idea.
After seeing the trailers (mech enhancement is a cool idea and it looked like it was done well), I was looking forward to ELYSIUM--I like Matt Damon's work and I liked DISTRICT 9. While I found the movie entertaining and the underlying socio-economic-political undertones were expected (although I believe I've found gaps in logic), I don't think I'd watch it again* because there were too many ideas taken from other movies/stories that I found it distracting/too predictable.
*I probably wouldn't change the channel if I saw it on TV, but I wouldn't go out of my way to sit down and watch it again.