Never thru hiked, but have sectioned Maine, New Hampshire and Mass.

Worst. A man and wife had all of there clothes stolen while they were skinny dipping in Maine. They were left on the trail about 3 miles southbound.
Me and my buddy brought the clothes back to them, we were norbound and put two and two together when we found them shivering by their packs.

Best. Prank reversal. As many know, it is customary to moon the MT Washington Train tourists as they ride by on the cog train.
The conductor pulled a pellet pistol and shot a guy in the arse with it. Heck of a good shot from a moving stance. Had to be there, but funny as all heck.