Unleased , untied dogs.
Cars that honk -as if I'm supposed to pull over and stop so they can pass.
Broken glass in the road.
Cars that pass close enough that I feel the air.
Anybody that yells at me.
Falling while clipped in.

Favs
Any driver that share the road - that is most people where I live.
Truck Drivers - by far the most courteous driver where I live.