Leaving the MK for the last time of a trip. Or for the last time at night. And really, leaving each of the parks (except AK) for the last time during a trip is a tad depressing, but mostly the MK.
I have sort of a weird....tradition? Ritual, maybe? The MK has to be the last place I visit before heading back to the resort to board DME. We always get a late afternoon/evening flight out so that we can go to the parks on our last day. I don't have closure unless I leave the MK last. Weird? Yeah. But it would kill me to leave the park the night before, and waking up the next day only to get on a bus and head out.