Depends, I guess, on what you mean by "emergency lighting".

Most people (myself included) would probably consider emergency lighting to be of the "Hey! What happened to the lights?!?" sort. An unexpected power outage, of unknown cause and duration. Then there's the "I know the power's going to go out." scenario. Hurricanes, for example. There's also the "I'm somewhere I didn't expect to need light" scenario. Dropped keys in a dark parking lot, maybe.

I have LED flashlights scattered all over the house. These work well for the occasional power problem. I used rechargeable AA batteries in an Arc LS during the hurricanes this year. I charged up several sets of batteries as the hurricane approached. I have a couple of bricks of alkaline batteries, but never had to use 'em. For the "dark parking lot" scenario I carry a small LED light on my keychain.

Next hurricane season, I'm going to find an area light of some sort. A small lamp sitting on a table would have been nice. Flashlights are great, but you usually have to hold them, and they're kind of directional. Something like your lamps or candles. And maybe a headlamp for those "changing a tire at night" situations.

LED lights can be cost effective, too. They usually have much longer run times than regular "bulb" flashlights, so you don't have to buy as many batteries. And the bulb never burns out, so they're more reliable. (Addictive too, it seems, but let's not go there. :-)