Out of my stable, probably the U2 for the same reasons others have mentioned. Long 40 hour runtime on low. Not as low or as long lasting as others, but the best that I currently have with a beam wide enough even on low to navigate.
Incidentally, we just had a search and rescue operation in our area for two hunters who became lost in the woods as night fell last evening. They were found in the middle of a swamp area suffering from exposure and hypothermia. From what I have seen on the news I think a LARGE part of their problem was being unprepared, and that appears to have included the lack of flashlights. Thus this discussion and others we have in these forums once again proved themselves to be worthwhile.