In January, Criterion released Burnout Paradise. Since then, the game has been patched once for bugs and then patched again with tons of free new content (Codename: Cagney). Coming soon, the world of Paradise City will be expanded again with another free patch that includes motorcycles and day/night cycles bringing allegedly 15 hours of gameplay, and once again for FREE (Codename: Davis). Later this year, more content is planned, including new "islands" that expand gameplay for specific types of cars.

I'm nominating Criterion for developer of the year because of their dedication to their product and to the consumer. Also, they make kick ass games. =P