Are there any LEGO movie/game posters?
If you subscribe to the Lego Club (availability depends on your location) you will receive the official Lego Magazine and often a free poster is included. The March/April 2014 edition contained a reversible poster with the Lego City theme on one side and the Disney Princess theme on the other side.

Occasionally, you may receive promotional Lego posters with some purchases at the Lego Shops (or online shop). Brickset lists a few of these here.

Bricklinks is place where you could purchase posters that are no more available from Lego. Here is a list of all posters on Bricklink.