LED

LED lights use a lot less power than their alternatives, but they cost a lot to buy in the first place.  The cost of saved electricity should soon make up for the initial purchase price - assuming the lamps last as long as they claim.  Sometimes they don't.

This LED lamp was the last one to be replaced in our house, and is the first one to die.  Fortunately most of the lamps last rather longer - maybe not as long as the manufacturers claim, but enough to jusfity their cost.