In reply to Roberttaylor:
Surprised no-one has mentioned the Petzl Nao (altho' I suspect it may be something to do with the price...)
However, if you can run to it, it's currently by far the best thing out there for mountaineering, biking, fell running - the lot.
Even though it's only a few grammes heavier, it makes things like the Myo RXP look like a candle (those extra lumens really are useful in poor visibility at night when you're trying to pick out descents from mountains).
Despite some initial scepticism, the reactive technology turns out to work a treat and battery life is excellent. The USB connector makes it a doddle to recharge just about anywhere these days - including the cigarette lighter socket in a car.
It's also extremely well designed with big chunky on-off switch for gloved hands, a fool-proof lock-out mechanism so it won't come on in your 'sac and an ingenious cinch mechanism for transport and storage so you never get your head band in a twist again.
I'd not been a fan of Petzl torches for many years, thinking they'd lost their way a bit with fiddly little buttons and poor build quality and had preferred American designs such as Princeton Tec or BD. But they seem to have have come storming back with this - I think it really is a game changer.