Oh those are good! Here's a couple that I have seen driving around our amazing country.
At an intersection in a small town, road construction had an intersection in a "Forward Only. No Turns" signage. However, because it was the weekend the street that ran through it was "Open for Turns". The problem was, on the left was a large trench (suitably barricaded) and on the right? A backhoe was parked across the road. Guess I'll turn at the next one.
As I went around a steep downhill State Road, there was a sign "Watch for Falling Rocks". As I was already geared down and going slow, I felt I was going slow enough. As I rounded a sharp turn, I had just enough time to grenade the brakes and dump the trailer brakes before I (gently) ran into the back of a tractor-trailer. The trailer was laying on it's side with a HUGE boulder sitting in the middle of it and the tractor was tilted at a crazy angle. I helped the ol boy out of the cab and he looked at me and said "Falling rocks? They got that part right!"
I love the "Motorcycles Use Extreme Caution" signs that are placed in front of what they call Bumps, No Shoulder and 'Rough Roads'. I'm already at "DEFCON 4" when I ride and when I see those signs, I think "Should I take a hit of speed, just to really be at "Extreme Caution" level?"
How about the 'Blind Person' crosswalk... How do they even know where the crosswalk IS, let alone know to stay in the lines?
Here are a few signs seen elsewhere, enjoy!