Got a few, some my fault and some that experienced by people I was with!
In February, took my brother on the big dipper. I'm shorter, and less muscular in structure, but we both ended up with a few bumps. I flew up into the lap bar, had a massive bruise spreaded across two legs, and I went faint for a moment towards the turnaround and we had a clash of heads. On the final bunny hops my brothers leg smashed against the safety signs nail, and he had blood running down from his knee, and a deepish cut that you can still see. That's all one ride as well.
I think the scariest moment has to be a lack of communication on the smiler a couple of seasons back in 2015. There was an empty seat, and the person batching told me that I could get on. Air Gates were opened as another train came in, I'd stepped one foot through at this point and the train was dispatched, and the air gates half closed on me very quickly. I would have either fallen onto the track, or got hit if the gates didn't close as quick as they did. Not entirely sure who's at fault here though to be honest.
At Grona Lund, i was winded by Insane as it came into the station, and my trousers got stuck, causing a lot of pain to an certain area :O I had to stop for about 5 minutes because I was in that much pain. I stupidly a few years ago, when i was quite young tried to stand up and touch the track on Wild Mouse, Successfully did so, but there was a car very close.
Worst of all has to be at Chessington, on Vampire. The plantage is rather long, and I've been hit by it on every time. One of the times, I'm not sure what it was but it got me, and scratched my leg, stung a lot, and there was a bit of blood.
I almost smashed my teeth out on my own on Lisebergs log flume, slid down the bench but put my arms out on the front part and managed to stop myself, so i was fine. Did shake me up however
As I say, SmilerGate was probably the most dangerous/scary.