By weight I'll bet it's a Zebralight, the bodies are really thin, and the alloy is really tough, the H600 models weigh slightly less than the battery.
If performance isn't a concern then even someone like me could make one much lighter, an led pre flowed onto a copper slug, a little plastic dome to protect it, a threaded plastic battery tube and some copper foil tape to complete the circuit... a resistor to keep the led from getting very hot or bright...
Probably possible to make a light that's a small fraction of the battery weight. Actually I have been wanting to make some spare battery holders like this, really low performance, 5-20mA discharge, just for keeping batteries clean and isolated, while serving as spare light sources without the weight... battery caddy/electric candle.
For high performance, quality, and light weight I doubt there's any better than ZL,
If so I definitely want to know about them.