A few:
The sound of an 18-wheels tire blowing as you drive past it while you're doing 70 in your convertible. I couldn't hear in my right ear for a couple days, and my heart rate didn't return to normal for a week.
That sick, heavy sound when someone gets hits in the face really hard. Sort of like combining the hitting sounds of a melon, coconut, and a slab of meat all in one.
A shot glass being ground in a garbage disposal (just learned that one yesterday
)