Ah, a topic that's become near and dear to my heart since last year's blackout.
Here's a post I made on candlepowerforums:
Blackout lighting To boil it down, my recommendations for the best bang for the buck in LED lighting would be:
Innovage 12-LED lantern.
Boscov's sale on Innovage lantern I'd never heard of this store until a couple weeks ago. Rite Aid also advertised this lantern at this price, but few were to be had - a store manager might be willing to order one for you, but I've spent nearly 2 months waiting for any result on this quest, and I tried to get them while they were still being advertised.
This is not the sturdiest LED lantern I've seen, but this is a great value. You shouldn't expect to get the same amount of light from these as what people are saying about Aladdin lamps, etc., but the light output should be sufficient for reading if you're sitting at the table this lantern is standing on, and perhaps a bit farther off than that. Uses 4D cells, and reports are it should give about 40 hours of light at its highest setting (it has a dimmer switch) and much longer life at lower levels.
Another great value, and a much smaller light, is the Energizer 2-LED folding lantern:
(click on this URL, then click "flashlight reviews")
Light reviews The 2-LED folding lantern is No. 40 in this picture gallery. It runs on 4AA batteries, folds to a variety of angles, has a hook on the bottom so it can be hung from a hook or string, and has two light levels (low and barely brighter). You should get days of constant use out of it per set of batteries. This won't give a whole room blazing light, but it's sufficient to read by if you set it nearby. The best part is the price - Office Depot sells these, in NYC stores the price is $3.29 - you could easily put one in every room for that price.
At the stores I've visited, they're at the checkout counters hanging with the batteries - very easy to pass by them because they're so small. These would probably be most useful as small area lights in rooms to allow you to navigate - like as a bathroom nightlight, etc., but you could use several to create a larger "area light" effect.
Dorcy "Cool Blue" LED flashlight
Dorcy Dorcy makes a whole line of lights of varying quality and utility - the one in question is shown as the center package of the three here, and that is the flashlight standing alone at the right. I've seen these priced at between $6.50 and $10 - at this price point, they're a good value. It's a squat, stocky light that's very sturdy, should run for several days continuously, can stand on its tail, has a folding ring that allows it to be hung and point down. A fellow at CPF said he used this light as a low-level room light, standing it on its tail and using the light reflected off the ceiling to light a small room. It has the added advantage of also projecting a narrow beam relatively far for using such a low-powered LED. I consider it a good cheap utility light, and a light I could loan to others without being worried about getting it back.
Those are the three fairly cheap lights that I have as "emergency" lights.
One more that I don't have any personal experience with, but has been recommended as another cheap alternative, is No. 35 on that "Light Reviews" link above. Apparently Target stores have had these on clearance sales (unsure if they're still available) for 3 for $10. They run on 1 D cell each, and should give low-level lighting for days on a single battery.
Good luck
Dave