My nitecore HC30 with 18650 battery is the best light I've used. Crazy bright, straightforward/useful switch function, stupid long battery life, can pull the light off the headlamp and use it like a flashlight if needed. It has been flawless for 3+ years, and I use it as my primary light all winter, and for all my backpacking now. It is probably not the lightest for the gram counters, and it takes a while to recharge the battery. Only downsides I can see.
Nitecore HC30
