Having tested a range of battery and dynamo lighting systems over the last 20 years, my favourite setup (by far) is a Busch & Muller Dymotec S6
dynamo, Lumatec Plus
headlight and Vistalight Eclipse
Together they provide a relatively cheap, reliable and hassle free lighting system. The Bosch & Muller S6 dynamo provides full power output (3 watts) at about 6km/hour making it ideal for riding rough bush tracks at night or checking out your favourite bike trail. I use the setup for night training on country roads, daily commuting to work and general touring. While it hasn't the power to blind oncoming cars, it provides more than enough light for sweeping down steep mountain roads at 60 - 70 km/hr and avoiding the odd kangaroo.
The Dymotec dynamo is smooth, highly efficient (55%) with adjustable contact pressure. It is one of the few side running dynamos that provides maximum power output at very low speed.
The Lumatec Plus headlight provides one of the best lighting patterns I have seen for a relatively small compact headlight. It throws a neat square pattern on the road with little wasted light as well as having a built in reflector and parking light. While the bulb support needs the odd tweak to maintain a good contact, the overall design is neat and robust.
The fact that I have now purchased six Vistalight Eclipse tailghts (myself, family & friends) speaks for itself. In my opinion, it is the brightest, most efficient LED tailight on the market. For really heavy traffic conditions I have two of these lights mounted on the back of my bike. One small drawback is that they do not work well with Nicad rechargeable batteries. I usually get about 6 months out of a pair of AAA duracells.
The cost of the above system with a single tailight is around $280.
My favourite battery system is the Vistalight Nightstick. A very neat, highly efficient lighting system.