However, only the second-best piece composed by John Williams it is!
Number one spot this rightfully belongs to (mmmm, yeeesss):
I routed that through my living room stereo, when the credits "wooosh" into view, there are some sub audible tones. Makes things a bit rumbly.
But listening to that made me think of a response tune. I am countering your John Williams with a Ennio Morricone theme:
(youtube's compression of audio is sooooo awesome by the way
)