I would use "Master and Commander" or "The Dark Knight" as a demo movie. Some others that come up are "U571" and "War of the Worlds" but so far I have yet to see a better HT experience than the excellent sound effects in Master and Commander. I saw Pan's Labyrinth a few months back, I can't recall how the effects were in that one(I think they were quite good)...I'll have to watch it again!

Half of communication is listening. You can't listen with your mouth.