Sorry if is a bit obvious but this blew me away when I first saw the 'Napalm Scene' in Apocalypse Now:
Colonel Kilgore: Smell that? You smell that?
Lance: What?
Kilgore: Napalm, son. Nothing else in the world smells like that.
[kneels]
Kilgore: I love the smell of napalm in the morning...