I have Energizer brand headlamps. I have one for around the house and I keep one in my bag at work. I have had mine for a few years. They have been dropped, bumped, thrown and the one I use for work made a trip through the washer and dryer and still works like new. You can get them at any big box retailer for between $15 and $20 depending on model.
These are the ones that I have.