You don't say why you need a really long throwing light as lights that are good for night hiking along good trails, night hiking off trail in rough terrain, running/orienteering/rogaining and mountian bike riding are all different in light output, bean profile, weight, cost etc.
My experiences with night hiking are almost exclusively 80/20 night hiking off trail in rough terrain/night hiking along good trails. I've have used over 30 different headlamps over the past 20 years and my current favourite is the Zebralight H51w, primarily for its range of outputs, very high efficiency and runtime using one AA (I always use eneloops with energizer lithiums as a backup) and good beam profile with enough throw and good spill, nice colour tint and its pretty light weight (althrough its no Photon, the extra capability more than makes up for the wieght increase IMO).
The Priceton Tec Eos is also a good headlamp as others have mentioned but heavier than the H51wn and the beam doesn't have the same throw.
If you want to go big, headlamps such as the Zl H600, Princeton Tec Apex or BD Icon may be better.
For UL trips, i've used a single aaa torch (4Sevens Preon Revo, no longer available) to good effect.
When hiking at night i've tried handheld lights, head mounted lights, lights around the waist, two lights etc, I keep coming back to a single head mounted light so I can point the light where I want to look and I have both hands free. I found while waist mounted lights and and handheld lights are better for definition of rocks and roots, my waist (hence light) was often pointing another way when I needed to see what was up ahead to the side or above or below my current position, and handheld lights I jsut found awkward.
Thats my 2 cents worth, if you had a specfic use in mind let us know.
Another forum worth checking out for headlamps is candlepowerforums.com.