Conical 5mm Wide-Angle LEDs are the most durable and brightest Christmas lights available.
Almost every professional Christmas light installer uses conical LEDs for their displays. Conical LEDs are waterproof and snowproof because the LED is injected molded into the plastic cordage. Conical LEDs are also 25% brighter than an incandescent indoor Christmas light. The brightness comes from the intensity of the LEDs and the magnification of the conical lens.
The Details On Conical LED Lights
Overall, LED lights are a great choice for Christmas because the lights almost never fail, and they are impervious to freezing temperatures. They are also much more energy efficient than incandescent bulbs. For this reason you can string up to 40 sets of LEDs together, and plug them into a normal electrical socket.
Conical 5mm LEDs are available from Amazon.