Tropic Thunder is a good choice. It features great cinematography and audio, it's also the best Ben Stiller film in ages.
Another film that really impressed me with it's great surround and brilliant visuals is The Spirit. Good to rent if you want to put your system trhough it's paces, not so good if you want to enjoy an actual film. If you roll with it it can be fun but most people find it pretty hard to swallow, firmly in Shoot 'em Up territory.