Wow, I'm shocked at the comments. I think it's between Alice in Wonderland and Toy Story 3. I think considering the kinds of posters that Blockbusters normally get, the Alice posters were quite fun and different from your average 'character portrait' campaigns. I think the thing that always bugged me about that particular Inception poster is that it's simply showing us a visual that we get from the film. Nothing original outside what the film has to offer. It should've been the other one that's more MC Escher-like where all the characters are on different planes of gravity.