I am a big fan of hub dynamo lights and now have them on all my bikes. My favorite are Busch & Muller D-Lumotecs, which havevery bright LEDs, almost like a mini-headlight on a car. They have a standlight feature so they stay lit for several minutes after you stop riding, and they can connect to a dynamo-powered tail light so you are visible from both directions. I love not having to deal with batteries. Apparently dynamo lights are very popular in Europe.