Here's one that was good for us but certainly a horror story for some others:

Just settling in on the right side of the 747, towards the front, for SYD-LAX. A guy sits directly in the aisle seat in row in front of us. He looks presentable but has the worst body odor I have ever experienced.

Just before doors close, a woman comes up to him and says, "I got someone to switch with you." The guy gets up and takes his things elsewhere, far away. His seat is taken by a different, non-offensive-smelling guy, who had walked over with the woman.

Wait about 20 or 30 seconds, and our whole section of the plane breaks out giggling. Lots of big smiles, eye contact and expressions of relief for three or four rows in every direction.