My needs in a headlamp are relatively specific because my primary use is for getting back to camp in the dark on backcountry elk hunts. A headlamp has save me from a cold night out more than once, too.

The light source must be an LED for efficiency.

I've experimented with plastic housings, but had trouble with durability. Now, I stick to metal housings for my headlamps.

Rechargable batteries make sense back home, but won't work on these trips because there is no place to recharge them. I always carry a few extra sets of batteries, so if the first set dies, I can easily be back up and running with a simple battery change. A relatively fresh set of batteries in the headlamp, and an extra set of batteries in my pack can easily get me through a whole night of hiking, if need be.

Also, I want two CR123 batteries to power the headlamp for long service life on a set of batteries. CR123 typically have higher energy density than AA or AAA batteries, and two CR123s doubles that. That's a lot of light energy in a small package.

I also want a simple switch that selects between 3 to 4 power settings. This allows me to conserve batteries by running the light at its lowest usable setting for the circumstances.

While not perfect, the headlamp closest to the above criteria that I have found is a Streamlight "ProTac HL."

[Linked Image from photos.smugmug.com]

[Linked Image from photos.smugmug.com]