Higher-end LED lights have amazing run times, and let you switch between "blowtorch" and "penlite" modes. I have switched everything over to LEDs.

Some of the inexpensive LEDs come with 3-AAAs and eat them like crazy. Gives people the wrong impression about the technology, and reliability is sometimes dicey. Shame on the people who market this stuff.

There's a good discussion forum specializing in lighting:
http://www.candlepowerforums.com/vb/

Also check out the very excellent:
http://www.flashlightreviews.com/