How about Sweet Movie and Pink Flamingos? I'm not entirely sure what is considered exploitation, as there are so many variations of it, but I'm sure those fit in somewhere.
There is also an excellent documentary called
Sick: The Life and Death of Bob Flanagan, Supermasochist which Wiki lists as exploitation (or, more specifically, shocksploitation). I was surprised to see it listed there actually - yes, it's entirely shocking, but it is also real - it doesn't just
look real. But anyway, it's great, so I recommend it.