Rode a corner on a trail I've done hundreds of times before, something went wrong, probably front wheel washed out, ended up needing a few stitches in my arm. Happened on a walking path that's sort of on the way up to the actual trails :/ Great embarrassment ensued.
Hit a sort of hip drop-to-berm thing, that we'd built a few days before, on my own. Went well off-line and ended up landing on the top of the berm, came to an abrupt stop. Snapped my visor and gave myself a nose bleed. Ended up with a scratch on my goggles that would surely have taken out an eye if I'd not worn them.
Last but not least, I'd cycled solo out 5 miles on road to get to Mabie, then rode to the top of the red (on a fairly heavy dh/fr bike). A few minutes into the descent I overcooked it into a corner, fell off and managed to hit a rock with my neck, cutting it. Scarred the life out of me until I realised I could still breathe, but swallowing and talking hurt. Cycled back down the nearest 'escape route' for a few miles, then back 5 miles on road, which seemed to take forever. Took a few weeks before the swelling went down and I could eat and talk normally again. Pretty scary.