My main rib-breaking experience was falling out of a white water raft while on vacation in Bali, and having the raft run aground on rocks with me underneath (yes as dumb as it sounds). One of the middle ribs cracked. I was on vacation with my ex, and the worst thing was when we went horseback riding on the beach ( :ghey: ) a couple of days later. The pain was excruciating. As I recall, it took several months to get back to normal.
A little more recently, I got the handle of my machete up under my rib cage as I was jumping down some rocks: it was in a scabbard on my belt, and the tip caught on a rock as I was going down and my entire body weight came down on the end of the handle for a moment and cracked the bottom rib. Once again, it took a few months to get better, but it was a lot less painful because it was the bottom rib.