That question is like asking which model of SAK is best or which cakiber is best. It bouls down to which one works for the situation or person.

Surefire's are good in their place.

If you want to light up the world you might want one of those multimillion candlepower rechargable spot lights.

If you want to just light up a small corner an led like a Photon.

A 6 D cell maglite will give a tremendous amount of light and act as a billy club. But is hugh and heavy. You are unlikely to carry it for very long.

Generally a good rule of thumb are AA maglite is about the standard maximum size for most kits.

Led's don't quit match the shear light out put of standard bulbs or high power bulbs. They do have the advantage of being much more power effecent and are more rugged.

A good compromise is the multi-bulb headlamp LED units. Good battery life and adiquate light output. Many of the multi-bulb outfits can adjust the number of LED's lit at anyone time so you can adjust the amount of light for the current use. That way you can conserve battery life as most of the operating time you will not need the maximum light available.

It is a balancing act between the weight and amout of light output. Also the longer the batteries last the fewer spares will be needed for the same period of time. Remember those spares quickly add up to weight and bulk.