Back when I was last camping (which is circa the stone age), LEDs didn't exist. So I used two gas lamps - one on a pole for general lighting and one screwed straight to the bottle that allowed the less adventurous to find the loo in the dark, and for inside the tent before bed, and then flashlights after that. They were pretty cheap and easy to operate, although changing the mantles was often required if they weren't packed carefully. The major downside though is heat - they kick out a fair amount which can make the tent hot at night, and they can burn a hole in anything (tent, fingers, sleeping bags, you name it) in a blink, so not so go around small kids.
I'll be looking to move to LEDs when I refurb my camping gear this year, and some of the suggestions here look great.