Add me to the "didn't like District 9" list.
X-Men: First Class
Go back a couple of years and add:
Children of Men
A little loose in the genre selection, and not all of these are necessarily the best (or even good in a couple of cases) but rather movies I think everyone should see.
I think there's a very real possibility that we'll see as many good to great science fiction movies on the big screen in 2013 as we've seen in the last 5 years combined.