People who pick things up in supermarkets, wander off, change mind and dump whatever they'd picked up, wherever they happen to be standing.
People eating/drinking stuff in supermarkets before they've paid for it. Are you really that hungry/thirsty that you can't wait 10 mins?
Microwave meal cellophane, where it doesn't peel off as it should and just the bit round the edge comes off.
Pour soup into mug, place in microwave, 3 secs before it's done it will bang, leaving you with a microwave roof Jackson Pollock'd in Heinz's best.
Fancy a quick game of something on the PS3 after not playing it for a while, sure, wait 7 hrs for all the latest patches and updates to download and install, by which time, the moment's gone.
When I've tried to be considerate, by pulling over to the RH lane to let someone travelling slower join a dual carriageway, why did you feel the need to proceed to race to my exact speed in clouds of Audi diesel fumes (no smoke, no poke, eh?) and drive side by side, thus trying to block my access to the next sliproad, grrrrrrrr.