You can buy a wake up lamp and aim it at your face while you sleep. They automatically turn on at a time you set, and the light intensifies slowly, like the sun. It’s a lot comfier than waking up to a loud noise.

I bought a Philips light-based alarm clock, which I liked, but it wasn't enough. So I built a whole-house system out of Hue bulbs and custom software:

https://github.com/wpietri/sunrise

To my surprise, the most valuable part for me was not sunrise but sunset. If the lights auto-dim in the evening, I go to bed on time, which means I wake up on time.