For me it is the 2 D Maglite in black. That to me is what is burned into my head as a flashlight. I don’t own one anymore and haven’t for many years but somehow that is the image I get first.
My first thought (before I even opened the thread was "Maglite"; wasn't thinking 2D persay, but i can see that being the first Maglite thought of (a 2AA would be close though).
That’s what I think of. And I can tell you why. When I was little, my granddad had a bunch of those things. One in his truck, one by his bed, one in the kitchen, one in a basket by the couch in the living room and many others spread out around the house. I would always mess with them. I would also get chewed out for shining them at people because supposedly these things could blind people.
But, if someone asks for a light, I always have one in my left hand pocket.