Ghost in the Shell, in general, has a sountrack that is... very Ghost in the Shell, and not all the time all that core cyberpunk. But there are some pieces that are, some are even personal favorites of mine in the entire OSTs.
Torukia is used, although not for the first time, at the hyperclimactic final episode of 2nd GIG. The good thing is that we already know the song and it has this super pumping effect there.
Part 6 (no other title, it was released in a disk containign previously unreleased tracks) is used in one of the epilogues to the very episode. SAC has at least another contender for a "GITS official imperial march", but the way this one evolves from ominous, to a little triumphant, to a moody state... I love it.
[video=youtube;pOHyMPHgS-s]http://www.youtube.com/watch?v=pOHyMPHgS-s&list=FLv-u1h-xhHVLpLxtFm50scQ&index=53[/video]
From the movies... Nightstalker. 'Nuff said: