The build up to battle... 'War Pigs' by Black Sabbath, or the Faith No More version.
For a big battle scene, you can't go far wrong with some Rammstein. Suggested songs by them:
Wollt Ihr Das Bett In Flammen Sehen
Asche zu Asche
Links 2 3 4
Feuer Frei
The Finnish rock band, Airut, who feature in FDF Mod are pretty good and they have a lot of free downloads on their website at
http://airut.info/records.php?language=1#Airut. Click an underlined title and the mp3 is yours.
'Bullets' by Creed would also fit a battle scene quite well.
I'd also go for some Prodigy songs:
Spitfire
Firestarter
Funky Sh*t
For any scenes involving evil bad guys oppressing the innocent, try 'Ich Bin Ein Auslander' by Pop Will Eat Itself.
Hope that gets you started.
Ade
;D