I can sometimes spend up to 6 weeks on a trip in varied terrain and countries so a good headlamp is essential. Zebra are comparable in price with Petzl - but I find the zebra, single AA battery with simple brightness options to be the best. Depending on the model it can go for something like 3 hours at 1400Lms or 4 months on the lowest setting (0.1Lm - guessing here)
http://zebralight.com/