The worst for me me was a pint of milk. This was back in the mid 70's before helmets and the evidently unopened carton hit the back of my head at about 50 mph and knocked me into the ditch. I'm lucky it didn't hit my ear.
The first time a dog was hanging out a window and barked really loud in my ear is memorable...
The anonymity of cars brings out the worst in people. However when you know the individual responsible and recognize them it can lead to some delicious revenge.
I was riding in a congested area (this is again back in the 70's) and this firecracker gets thrown at me from a passing car. The car was only slightly faster than me I was able to get a ID on the kid responsible. He worked with me at a screen printing shop! So Monday when he's working and is concentrating on his task I light a M-80 and walk it over to his station and lay it at his feet. The reaction was everything I hoped for.
With the increased use of air conditioning and because this is generally a "crime of the moment" it seems the frequency of incidents like like this are a little rarer. Unfortunately I am being "buzzed" frequently nowadays. This is a disturbing trend.