Nanoleaf 12W LED

Best for Maximum Life Span

All LEDs are energy efficient, but the Nanoleaf's folded-design goes further. The tactically positioned diodes and perforated frame avoid the need for external heat sinks, making it the most efficient 100W-equivalent bulb by a mile (36 percent less electricity than the Philips). The light is a bit harsh, but put it under a shade and you can forget it for 27 years. [$50; amazon.com]