This is a bit premature as there are lots of movies I have yet to see, but here is my top 5 list so far:
Honorable mentions - Drive, Hugo, Win Win, The Skin I Live In, Cave of Forgotten Dreams, Hanna
5. 13 Assassins

Director Takashi Miike is most well known for his propensity for extremes (Audition, the Dead or Alive series), so it is a pleasant surprise to see him reign in those impulses and create a full-bodied samurai epic in the Kurosawa tradition. He seems to be saving all of the crazy for his upcoming Phoenix Wright: Ace Attorney film.
4. Senna

Entertaining, accessible documentary about the life and tragic death of F1 driver Ayrton Senna, a man who truly lived life in the fast lane, focusing on his tribulations breaking into the European racing leagues as a Brazilian and his rivalry with Alain Prost.
3. Melancholia

As the title implies, this film examines a person afflicted with great depression and sadness, a condition which is as destructive externally as it is internally, manifesting itself in grand, literally apocalyptic ways. As with all Lars von Trier films, it is challenging and defies, subverts, and complicates film convention. I wouldn't have it any other way.
2. Poetry

An elderly woman on the verge of Alzheimer's that finds solace in poetry in this disturbing Korean drama that explores the concept of 'what lies beneath', whether within a person, town, or culture as a whole.
1. A Separation

An absolutely devastating film about the tribulations of an Iranian family amidst sociocultural, religious, and criminal interests. It is a sobering look into a conservative Muslim society that many revile and find alien, that in reality is just another manifestation of the human condition. The greatest triumph of this film is that it does not try to make those kinds of grandiose statements and instead plays out like a simple, strong, stunningly acted drama, and lets us make our own conclusions.