I agree with bluesky636 that the opening battle scene in the M&C is excellent audio demo material, however the PQ is only so-so since it was filmed to looked like the battle was in the fog.
You may want to consider the first chase scene in Casino Royale
, it has stunning PQ and rocking AQ and is about 5-10 minutes long. Excellent demo material.
If you want to consider another type of option, look at The Police: Certifiable
; outstanding PQ & AQ. I just watched this BD a few days ago and loss what little was left of my hearing