I second wid's Eagles suggestion. It has some great surround work in it, you really get the sensation that you are in the audience.

Star Wars : Phantom Menace - Pod Race scene, has some really good surround experience as well.

U571 - Depth Charge scene will test out the M60s and subs.

Saving Private Ryan - Beach landing has lots going on it.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70