People in mobility scooters who drive right at you on the footpath and don't move to steer around you so that you have to step aside for them
Seeing able bodied people (usually middle-aged women) get on the bus and plonk their backsides in the seat right behind the driver reserved for the disabled even when 3/4 of the bus is empty.
Mothers who park their 4X4's on the crossing right outside the school and don't get out of the car with their kids but sit there blocking the traffic until their pudgy offspring are inside the gates after having turned to wave at mum 25 bloody times.
Mothers who consistently send their kids to school without a snack for break or lunch (I am a supervisory assistant in our local primary and bear witness to this kind of laziness all the time....)
People who look the other way when their dog is pooing on the footpath ad then carry on/people who drag their dog along while it is pooing so that the poo is dotted along the footpath
Queue jumpers - sorry but Asian tourists (Chinese, Japanese, Malays) seem to have this bad habit in their blood.