LED flashlights produce very high levels of illumination - but they don't use anything like as much energy as a standard flashlight fitted with an old fashioned bulb would. That means that you can get a high level of light from a much smaller flashlight - less weight and bulk for you to lug around with you.
Another advantage is the fact that the bulbs are robust and long lasting. In all probability, you'll never have to change the bulb in your LED flashlight.
HEre's a brief list of some of the best LED flashlights on the market right now: