Here's one I feel and enjoy but have a hard time explaining to people who don't experience it, and have no word for:
The sense of potential that comes with being alone in a normally-crowded space.
Like walking the halls of an empty hotel during or right before a convention, when nobody is there yet (or awake yet, or awake still), and there's this electric sense of anticipation, potential... It's not quite excitement or enthusiasm, maybe you don't actually care about what's going to go on in that space at all, except that you know something is but not yet and that has an energy all its own.