The worst case of turbulence?
I was chatting to a friend (now flies for BA) about various flying trips I'd done and was explaining about a trip a did back from Scotland down the East coast once. The forecast was not brilliant (and with more experience now, I wouldn't have done the same trip!). Winds were forecast 50kts over the highlands, gradually decreasing further South. Cloud base was approx. 3000. (I had no IMCR at the time so was stuck under).
We'd just passed North Berwick, a few miles inland from the coast. The trip had been relatively uneventful and the further South we got, the more relaxed we were until the aircraft suddenly dropped with a huge sounding "BANG". The drop was so severe, I was lifted out of my seat, hit my head on the roof, headset came off etc. We were both suitably shaken but unhurt by it.
The friend I was explaining this to had never experienced anything like this (certainly not in a light aircraft). It made me wonder what the very worst cases of turbulence might be - and also what might be dangerous to the aircraft and me!