The driving one that keeps happening to me lately, driving on your basic two lane roads in a small city... Approaching a traffic light, intending to go straight, but driver just ahead is waiting to turn left with a line of cars coming in the opposite direction. If they would just keep to the left of the lane and pull up into the intersection, I would easily be able to get around them and go on my way, but they remain in the center (or even right) of the lane and keep back where there is no room to get around.
And then there's the same situation but I'm the driver waiting to turn left. I keep to the left of the lane and pull up into the intersection, giving the person behind me plenty of room to get around, but they follow too close behind me and either get themselves stuck there or are just content to wait. I shouldn't care, but I see the line of cars building behind me and I get frustrated by that person anyway.