Mine:
Back in the days when I still attended University, one of my hobbies was making small movies with other students.
One day we were filming (a rather bizarre persiflage). My role was (appropriate for my height) a karloff-like monster.
We were filming the death of that monster during a police raid at a deserted industrial area (former steelworks). I ran away, was being shot, fell spectacular onto the gravel while tossing my sabre away.At first, all went well. We did a few takes until we ran out of blank cartridges. I was glad, because being completely unathletic, I was pretty much exhausted. Suddenly one actor discovered he still had some in his pocket, just enough give all guns another, last shot. So the director decided to go for a last take.
This time I was too exhausted. I threw myself into the gravel again, but I wasn't able to throw away the sabre with enough force. Instead of away, it went up. I didn't notice that instantly. I rolled on the ground came to rest on my back and opened the eyes...
OH SH** !!!I saw the sabre directly overhead, tumbling in the air and coming down...on me! It actually felt like slow motion, but there was nothing I could do. I was like being hypnotized and watching the blade coming down onto my head...
Then he hit me above the upper lip, right between nose and mouth. Didn't hurt as much as I expected . Fortunately I hadn't been hit with the tip, and the blade was just sharp enough to pierce my skin down to the upper jaw but not able to hurt my bone. One inch lower, and I would had lost a few teeth. One quarter revolution more, and the sabre would had impaled me...
Funny enough, I was carrying so much makeup that nobody didn't notice that wound.. not even me.

Only when I got home 30 mins later and removed the makeup in the bathroom I discovered the clean, gaping cut.
Well the doctor that stitched my wounds at the hospital made big eyes and could barely hide his grin...