I have an old 3D Maglite (upgraded to LED) that I use for situations of imminent major abuse. It hasn't failed me yet, no matter how many times I drop it into the sump pit.

For most things, I try to find the "Quark" or "RSK" of it's type. The RSK knives perform brilliantly -- way better than some more expensive knives I've owned -- but aren't so expensive that I'm afraid to use them. Same with Quark flashlights.