4.
They finally made it to the Grand Canyon. Dean had been bugging Sam about it for weeks until the younger Winchester threw his hands up in exasperation and defeat. The day after they arrived, however, a trio of hunters caught their scent and spent the next few days doing their best to make their lives miserable. But Sam and Dean knew all the tricks of the trade. They played with the hunters until they were tired of the chase and slaughtered them in their own motel room.
Sam and Dean grinned at each other over the corpses and Dean suggested they write "Winchesters were here" on the wall in blood. Sam accused him of being childish but Dean only flicked him off and did it anyway.
It turned out to be a bad idea because every hunter in the Midwest promptly descended on them. They spent four months trying to cover their tracks and eventually crashed at Bobby's just like they used to, back when they were humans on the run from demons instead of the other way around.