The absolute best flashlight to be lost in the woods with is the one you have with you at the time (assuming that it works). Planning ahead for the worst makes anything less than the worst case scenario little more than an inconvience. I have a rather small pouch (about 4" x 6") with a whistle, matches in a waterproof container, a film canister with cotton balls smeared with vaseline (these can be used as lip balm or as fire starters that burn long enough to light even wet kindling), a commercial "metal match", some water purification tablets, a large garbage bag (can be used as an emergency poncho or a shelter), a small basic Silva compass, a knife, a CMG Infinity Ultra (because of the claimed run time of 25 hours), a small wad of TP in a plastic bag, and a very abbreviated, very basic first aid kit. I keep this in the car and just grab it whenever I leave the road. With this and some water (I usually carry a couple of bottles in the car to have something to drink on those long, heavy-traffic commutes that sometimes happen when there is an accident), you can spend an unexpected night in the woods in relative comfort. It won't be like home but you won't be in too bad a shape.
I guess the most important thing to remember is "Failing to prepare is the same as preparing to fail". When it comes to survival, failure is not an option.