Awesome Music: Star Trek VI: The Undiscovered Country
While most of the soundtrack is just all right, Cliff Eidelman's Overture piece, played during the opening credits qualifies simply because it builds to a climax that is topped off with Praxis exploding.
Also, the sweeping music that plays as Kirk, McCoy, and Iman make their way across Rura Penthe.
You also have "The Battle for Peace" which accompanies the entire battle over Khitomer. In particular, you have the slow but steady build up in the track as the Enterprise takes more and more damage, and Spock and McCoy are desperately trying to finish modifying the torpedo to take out Chang's modified Bird of Prey.