I was (mostly) rolling with Elysium just fine until the third act, when it went right off the rails. None of the payoffs made sense and I couldn't help but start thinking of all sorts of better ways to go with them.
And the final ta-dah! completely undercut the entire premise by showing that the central issue that drove the entire plot could have been easily solved from the very beginning.
I'd go into detail, but I'm hoping Elysium will be very high on our to-do list when we re-convene after the holiday so we can really get into it.