People who walk along staring at their mobile phone. They are like a stone in the shoe, impeding movement. This is especially irritating in cities.
When someone says "With all due respect..." and what follows is invariably less than respectful.
Stock phrases such as "to be fair; to cut a long story short; at the end of the day; I hear what you're saying...". Rarely do these phrases serve any other purpose than to fill a silence.
Media sites that deliberately seek to goad or annoy. Why do they feel it necessary to spread misery and anger?
People who check their mobile phones in the middle of a conversation or meeting. How rude!
Dog excrement on the pavement.
People who throw their rubbish out of car windows. This behaviour is simply lazy and inconsiderate.
People who complain about the behaviour of others, but smile and accept it when in that other party's presence. *
People who say they are going to do something, but never do.
*I may be guilty of this, on occasion.