I EDC an Arc AAA flashlight attached to a keychain. It is one tough light! I've carried it for many years and it shows NO wear ... at all. Amazing.

I didn't like having the LED bulb exposed, even though they say it is real tough, so I went to the local Ace Hardware and bought a plastic dowel cap (not sure what its really called) that was just a tad too tight, and then I sanded the inside of the cap just enough for it to fit snugly on the light. Its worked well.

A few months back I lost the keychain (I found it a few days later) and bought a Fenix E01 ($13) to replace it, but never used it.

Though I don't really use flashlights much anymore, I do carry a Streamlight ProPolymer 4AA. It is amazingly bright (for finding gear/Scouts in the woods), tough, and I like plastic because it doesn't scratch other gear (and hides scratches on itself) and feels warmer in winter.

I have several UK 4AA LED lights but I've found their switches to be tougher to press than most other lights. The kids really couldn't use them because they struggled with the switches.

I like Fenix lights a lot, though I've pretty much stuck to the 123 lithium batteries for those.