I cut the tips of my index, middle finger, and thumb off of my left hand (through the nail) in a similar manner of the pic that has been posted. I was in the back yard sharpening a machete on a bench stone (holding it in my left hand). I watched them fall into the yard and my dog promptly ate them. I tried to catch him before he got to em, but he wasn't having it. He ate em.
I've cut my hands/fingers too many times to count. The worst was probably the previously mentioned dog treats, or maybe the 15 stitches down my left thumb. Maybe the time my wife sliced through my right thumb all the way to the bone and through my nail. (6 stitches and lost the nail for a while)
Come to think of it, I've actually stabbed myself in the stomach. I was chopping small limbs off of a tree in the front yard with a Kabar USMC knife. I brought the knife around in a strong snap cut. It whipped right into my stomach about 1/2" deep. Bled like crazy. I just put Neosporin in it and super glued it shut. Still have the scar.
When I was a kid, me and my friends were playing mumbledy-peg. The knife was a folding filet knife with serrations on the spine. I dropped it off my forehead and it stuck all the way through my right foot. We all just stood there looking at it. It was trembling and pulsing with my heartbeat. We all freaked!!!! I pulled it out and ran to my Dad who was in the garage. He put monkey blood on it and wrapped it up with two cotton balls and electrical tape. Healed fine - still have the scar.