Gravity.
My favorite movie of all time is Sunshine, so hearing all of the hype for this one made me think that perhaps Gravity would steal that honor.
It almost did.
Gravity and Sunshine are very different movies. Sunshine takes its time and allows for long moments of introspection. Gravity has pauses, but for the most part it is an intense race for survival. As such, it never allowed me to sink into the movie the way Sunshine did, so Sunshine for me is still the best. But Gravity has the most realistic CGI that I have ever seen, and I still don't know how they did some of the floating effects. It also usurps Revenge of the Sith as making the most dramatic use of a certain spaceship situation which I will not state here as it may be construed as spoilers. Gravity also genuinely surprised me in several places, something that gets harder and harder to do.
I saw Gravity in 2D. It looks like one of the few movies that would be better in 3D, but 2D was absolutely wonderful for me.
I would not change a thing about this movie. Perfect ten out of ten.