Light-emitting diodes, or LED lights, have the longest life expectancy at an average of 20,000 hours. CFL light bulbs have an average life expectancy of 10,000 hours, while both halogen and incandescent bulbs have an average life expectancy of 1,000 hours.
Energy Star and the Illuminating Engineering Society, or IES, created the testing procedures used to rate LED lights and determine their life expectancy. They use a fraction of the wattage of an incandescent bulb, giving them a longer life expectancy and making them more cost effective in the long run. Failure of an LED light is possible, but many come with mechanical failure warranties.