I was thinking brands in general. To be fair, it probably should be stated that Every brand potentially has some bum models or versions of lights. Having said that, one could say XXX brand is junk, and XX brand is the best and vice versa with both being true at some point in time! What a perplexing conundrum!
ncgrass,
Good idea, A example of what I was thinking: Surefire C series with a Malkoff and the twisty tail cap. As a bonus, twist action lights typically have less moving parts to fail or need cleaning. But....you may need to clean treads as some point?
Personally, I like Armytek, however based on my personal experiences and others I have read, I wouldn't consider that brand, in general, to be worthy of the OPs question. But, like I typed above, Armytek may have a single model that is. But on average, nope.
There was a thread that was sorta like this one: I can't find it, it was something on the order of "Lights that always work". There were some good info in it.
I will add: I have several "budget" lights that I would trust my life with. I have several expensive or customs I wouldn't. And again vice versa! lol I say all this to repeat, there can be many variables in this thought exercise.