The worst injury I've had is probably all four of my wisdom teeth being extracted. Not an accidental injury, but was the most major surgery I've had so far - My gums had to be sliced open, and the tooth extracted from inside my jawbone - It took about four hours and I was fully unconscious for it. It really hurt and made my face swell up like a chipmunk. And it was disgusting having stitched up wounds in all corners of my gums.

If we're only counting accidental injuries, I guess my worst injury was kicking a door frame by accident. It was incredibly painful. I don't usually scream from pain, but I screamed at the top of my lungs that time.
My two smallest toes were bruised to hell, so I couldn't put any weight on them. Even after the bruises faded, they didn't feel right for weeks afterwards, the joints felt stiff and painful to move. I'm not sure what happened exactly, but thankfully they healed eventually.

I cracked my head open once. I refused to go to the hospital and get stitches, and it healed by itself after a few weeks.

Well, I have a most serious and a most painful. For the serious, I got a nasty concussion. I am a theatre guy, and we were building a set on stage. Someone was working the fly system (the rope and pulley system that raises and lowers set pieces, lights, etc). He didn't shout out that he was lowering one of the batons (big bars). He was lowering them, I was right below working on the 2nd story of a house we built on stage, and the 120 pound bar bonked me right on the back of the head. Luckily, I did not fall off the roof, but I blacked out.

For most painful, I was about 5. I wasn't tall enough to see myself in the mirror in the bathroom while brushing my teeth, so I would climb up on the counter. When I was done, I hopped off. Our cabinets had these handles that went vertically (up and down, not side to side), and the ends extended an inch farther than the handle part. So it was basically a blunt but pointed end. When I hopped off, I was close to the cabinets, and the end of the handle impaled the skin on my left side. My feet didn't ever reach the ground. I was hanging off the floor by impaled skin on a handle. It was horrifying. 

rcarter2 :  Imagining that just made me wince so bad. Wow...  I can't imagine going through that, but especially as a young child!

I feel left out, but I'm sure it's a good thing. LOL I've never fainted, passed, out, or broken a bone. In fact, I really haven't even been stung by any bug.  My mother was just way too protective. My other siblings have all had some more serious injuries (though still not a broken bone between us).

I can't even think of a wound that caused me to bleed profusely, in all honesty. It's kind of a weird thought.  the thing that freaked me out the most was stepping on a sewing needled and having it -completely- immersed in the heel of my foot...

Ehem...I guess I have been pretty lucky throughout the years to not have anything much too serious concerning health and such...but I did pass out once for standing too quickly (so stupid of me haha), so all the oxygen in my brain rushed down and when I passed out, I hit my head on a chair, causing my laptop to fall on me...in my tender male parts. Lovely. 

That sounds stupid, and yes it is, but I have been lucky not to break a bone or really suffer through anything too horrible.

Singelli : Haha. Yeah. Not fun at all. I still remember that day pretty clearly. My older brother (2 years older than me) was in the bathroom with me when it happened. I remember him jumping up and down in panic and then he ran out of the room screaming. Last thing I remember about that is my mom rushing in and lifting me off the handle. I still have the scar from that one.

Mr. Zed : Rolling down 15 steps (yes I counted), and getting a steel door opened to my head afterwards. It all happened in a ship, my dad heard me crying and rushed to where I was, unfortunately my head was right next to this door.

Annette : Thanks for that image... I'm getting all 4 wisdom teeth removed (cut out from my gums) in a couple weeks... *cries*

Most painful... spraining my ankle. I was running through the woods, jumped onto and immediately off of a log, and landed really bad on my ankle. Totally sprained. I had to walk home too, and tried to catch up to my friends first (walked on it for at least half an hour, had to use a log to help support my weight. I couldn't handle the pain otherwise). Hurt like crap, and took a couple weeks to heal.

Most serious would be when I broke a rib. I was riding my bike (bicycle, not motorcycle) and decided to try no-hands. Handlebars twisted, and one of the handles (kids bike, so the handles were really small) hit me right a rib. Still feels weird to the day, but I never went to the doctors.