Supermarket trollies, I hate the fact that they are tethered and require pound coins to remove them - I appreciate that it is to deter people from stealing them but they still do anyway. Some trolleys are in such a bad condition so you have to go through a few to find one to be able get the coin in or one that won't get it stuck at the end of the shop. Even more irritating finding no other trollies there to push the coin out with at the end of the shop. There must be some other device they could use to release the coins.