So true, there are a plethora of threads about this subject. But I can't resist
Try Master and Commander, first attack of of the Acheron. Or the final battle. Woof (no pun intended)!
Or DTS Demo disk #9, the Jurassic Lunch track (track 13? I'm doing this from memory).
Lord of the Rings, Return of the King, the Charge of the Rohirrim at the Battle of Pelennor Fields. If you have the right sub setup, this turns a standard (if unconventional) cavalry scene into a religious experience.
You can also check out the site of Those Who Must Not Be Named (look at the sub in my sig) for an exhaustive list.
Cheers -