Not to sound like one of those super-cool hipsters, but I've been a Christopher Nolan fan since Memento, which I thought was the best film of 2001 and maybe the whole decade. You people who didn't start loving him until he made some Batman movies ... well, I'm better than you, is my point.
Insomnia, The Prestige, and the Batman films were all worthy followups, but it's with Inception that Nolan re-achieves artistic greatness. Like Memento, it's a fascinatingly complex story about memory, perception, and the untrustworthiness of our own minds. It's also extremely inventive and entertaining; highly intelligent but not baffling or inaccessible. Like the other great film of the summer, Toy Story 3, it wins points for trying to convey difficult, ambitious themes, and even more points for actually succeeding. Many films try to do a lot less than this and still don't meet their goals.