Couldn't agree more that some peds and cyclists seem to believe they're trying to take part in this years Darwin awards.
Still, worst I had was probably in Malaysia a few years ago. Had been lent a Toyota pick up (don't ask me which). Was on a dual carriageway with a 80kmph limit, in the right hand land, probably doing about 50kph (accelerating as I left the town I was in), only to find a cyclist just to the right of my lane, no lights, nothing. Missed him by inches as I had such a short timespan between spotting and being able to do something about. Probably the closest I've ever come to hitting anyone whilst driving.