I have broken or lost:
Photons
ASP
Inova
Some no name mini maglight looking thing with a weird battery I have never been able to find that I got from Micro Center.
And dozens of those half crap swag squeeze lights that are really only good to hack into something better.
So finally I gave up and bought a bunch of these off of Amazon(picture for reference, hand for scale):
USB LED Flashlight
I always have a power bank with me and USB slots are everywhere now. So this is what I use. This coupled with a tiny snap ring and a true utility snap hook.