Maybe you've already done the righteous thing and swapped out all your energy-sucking incandescents and not-universally-useful CFLs for long-lasting, mercury-free, energy-saving LED bulbs. More likely, you've dropped in a few here and there, with mixed results. LED bulbs can still be cold, alien-looking things with odd shapes, splayed fins, and dazzling price tags. But they keep getting better—and cheaper. If you haven't already, now is the time to start making the switch, and we're going to explain how and why.