Some of the Chinese CREE based lights are VERY BRIGHT, and relatively cheap.
Personally I prefer a bit of a wide angle beam rather than a straight spot ahead beam.
However, the problem with the cheap Chinese lights is that when you point the light at the horizon, it illuminates as much above the horizon as below, and ends up being extremely bright in the eyes of oncoming traffic, or other trail users.
The Specialized Flux Expert (and maybe other Specialized Flux lights) are designed to cut off somewhere below eye level, which also means the maximum amount of light is projected onto the road. A bit expensive, but it may be worth it.
See review:
REVIEW: Specialized Flux Expert Bicycle Headlight - Photo Intensive
Unfortunately they're a bit expensive
