Adjustable wall plugs
They are also known as 360-degree wall sockets. The name says it all; they can rotate full 360 degrees and come pretty handy when you want to plug something, but some furniture pieces block the socket.
It’s also useful when an existing appliance is plugged into a socket in a way that prevents you from placing the new piece of furniture next to the wall. It’s one of those products that you don’t always need, but when you do need it, it’s irreplaceable.