LED Christmas lights are efficient — they use 90% less energy than incandescent bulbs. They are also brighter, less prone to breaking, and cool to the touch.

Less optimal is the fact that almost all Christmas lights are made in China using questionable labor practices, and then transported half way around the world.

LED Christmas Lights 

You can find LED Christmas lights at Amazon. You can also find some snowflake-shaped and color-changing Christmas LEDs from Environmental Bulbs.