You can never go wrong with Beethoven's Choral Symphony. 70 minutes of absolute musical genius.https://www.youtube.com/watch?v=QfrAXZC7GKA
The 1812 overture is also great for when you start in Russia and have to fight an invader. https://www.youtube.com/watch?v=UfCPVUQZ-6g
That version doesn't use cannons though, better when they use actual cannons for the end.
Edited 2/26/2015 18:33:36