I'm drawing a blank, but I can think of smells I wish I'd not smelt!
When the guy came to pick up the bone&fat bin (one of those big outdoor trashcans in which all of the useless chunks of meat thrown away by a meat department in a grocery store lands) at the height of summer, only to find a second, much older bone&fat bin hidden away in an abandoned freezer (which, rather than being cool, was warm as shit).
The stench of rotten meat (I saw it. It was green and black) filling a 32-gallon trash can and being dragged onto a truck in 100-degree weather.
Originally Posted by ZeldaQueen
An inexplicable string of deer roadkill on the highway from Pittsburgh to Ohio.
That's all the time. Generally worse between Morgantown, WV and Pittsburgh.
EDIT: and it's not really inexplicable, as not as many people are into hunting as they used to be and the land there is pretty good for deer.