May be in the bargain category, but I've carried one of these daily for about 4 years, and never had a problem with it. I keep Lithium batteries in it.

http://www.energizer.com/flashlights-lighting/flashlight/Pages/tactical-metal-1aa-1-watt-light.aspx

Recently bought the new version that has 85 lumens and like it as well.
_________________________
In omnia paratus