I'll throw in a plug for Fenix flashlights, a small one, but a plug nevetheless.
Over 10 years ago I bought a Fenix LD22 at REI. Main reason for getting it at REI was at that time they still had a lifetime guarrantee on everything they sold.
About a year or so ago I pulled that flashlight out of the door pocket of the truck and the batteries had corroded. My fault but no worries because REI would cover it. Right? Not so fast. They had to have proof of purchase and I could not find a reciept for the light. A year or two from now when I'm not looking for it I will come across it.
So I decided to send it to Fenix anyway to see what they would do. Wasn't holding out much hope of anything. But, Fenix actually determined the problem was in the end cap. Maybe, maybe not caused by the corrosion but they offered me a decent discount on a new light or they would replace the end cap and it would work - how long who knows.
I thought that was a decent trade off. I would have reather had a brand new updated model but my flashlight works fine and I can still use the discount if I decide I want to do so. So, Way To Go Fenix. They exceeded expectations.