I was reminded of this feeling recently when re-watching Laputa: Castle in the Sky. If you have seen the film, you will know the scene I am talking about - it is the one in which the half-damaged robot, which had previously been thought defunct, is suddenly activated and single-handedly destroys an almighty fortress and, presumably, kills hundreds of people in the process. Sadly, YouTube only has this short Metallica-ized clip, which doesn't do it justice, but still:
Miyazaki loves these moments - his earlier films are full of them. But so does Hollywood. You will be familiar with these examples:
There are plenty of others - in literature as well as film (China Mieville, for example, has always struck me as a writer with a keen instinct for this sort of scene).
Where does this feeling come from? Partly, it is pure child-like love of destruction. Partly it is a kind of received glory: as though one is somehow vicariously edified by a naked display of power to which one is not subject. Partly it is sheer anticipation, combined with a feeling of hidden knowledge: you know what is coming when the Terminator walks out the door of the police station, but the police - those poor fools - do not, and that can't fail to excite. And partly, perhaps, there is even a sense of the sublime in these moments - a sort of transcendant beauty in the aesthetics of strength and might.
In summary, human beings like watching a god-like entity squish things. But we don't appear to have a single word, at least in English, which describes the sensation.