Inception will undoubtedly be number one soon, but as of now, from the limited amount that I've seen thus far:
1) Shutter Island
2) Kick-Ass
3) Toy Story 3
4) Splice
5) Iron Man 2
I imagine by the year's end, Splice and Iron Man 2 will have been booted off this list, considering this list of anticipated 2010 films that I've yet to see/that've yet to come out:
-Inception
-Valhalla Rising
-Black Swan
-Paul
-Buried
-The American
-The Killer Inside Me
-Hesher
-Blue Valentine
-True Grit
-Four Lions
-Cyrus
-I Saw the Devil
-Catfish
-Winter’s Bone
-Jack Goes Boating
-Enter the Void
-Exit Through the Gift Shop
-My Perestroika
-The Ghost Writer
-Red Riding Trilogy
-Dogtooth
-Your Highness
-Monsters