There's a lot to be said for an LED flashlight that runs off of AAs. A modern unit with lithium primary batteries sits in my wife's emergency kit bag and performs very well for its size and price. This is an excellent recommendation for many flashlight users.

For myself, I frequently avail myself of the longer runtimes and higher output that other battery chemistries allow. Do I always need those things? No. But I've needed them before, will almost certainly need them again, and they're sure nice to have at other times.