I broke my arm falling off a horse when I was a pre-teen, but I don't remember it or the pain very well.
Recently, separating a dog fight at the dog park. Big pit attacking my beagle, so I got in the middle (it had already torn a big hole in mine's ear and had him by the throat ) and got my hand all mangled. Honestly the most painful part was when the nurse at the ER flushed the wound with water. It was really deep, and he forcefully shot water into it, OWWW.