NiteRider makes a great bike light. 10 or 15 watts is enough light to see your way on the road or on a trail. They also sell dual beams. But their brightest lights are HID bulbs, at about 350-400 $$. This company is based in San Diego. The lights come with a lightweight battery pack that you tie to the cross tube. They can also be helmet-mounted.
Some of them are digital and have a digital readout display of battery power levels. The batteries generally take between 5 and 9 hours to charge, and they run between 2:20 and 4 hours, depending on usage and intensity.