Acebeam M50 AL
I keep this on my car keys for when I need a light in emergencies. It's perfect for that. I bought the Osram KW version for a longer throw. I would put the visible throw at about 100m, but after 50 meters or so, it doesn't illuminate much. It's certainly very bright for its size and is more than good enough as a keychain light. The twist on and off mechanism is okay, it's quite stiff so prevents accidental illumination and it holds together well and is easy and quick to charge. Very good value for money overall!