For backpacking (and home emergencies), most of the stuff popular only 10 years ago - from gasoline and propane lanterns to Cyalume lightsticks - now is almost obsolete.  Modern LED gear not only will save you carrying in all those heavy spare batteries or propane cylinders - but will save you a fortune in not having to buy them!
   Tiny LED on-your-head flashlights - notably the below one that Streamlight makes that clips to your ballcap or an (included) headband - will run two week's worth of nights on a single set of three penlight batteries if you use their low setting, and it is definitely bright enough to do all indoor chores or even outdoor ones like getting the generator out and refueling it.  They definitely will light up a tent well enough to do almost anything - and are very robust.  They are pocket-size - so you can literally carry them everywhere in emergencies.  These lights - including the headband accessory - sell around $20 on Internet Gun Show.
   A variety of LED lanterns - offerring a month's worth of lighted nights on one set of three "C" batteries - are now available, but not as robust as the Streamlight ballcap one.