Fast food restaurants that sell what they were originally created to sell.
McDonald's = Hamburgers
Arby's = Roast Beef sandwiches
Kentucky Fried Chicken = Fried Chicken
Pizza Hut = Pizza
And on and on.
The real "treasures" of the fast food kind are the places that have never deviated from their original menus. An example in Seattle at least is Dick's Drive In.

I am old and yet young enough to remember going the old McDonald's restaurants before they tore them all down.

Sounds cheezy, but going to McDonald's was a real treat once. I remember going with my cub scout troop and getting a tour and shit of the kitchen.
That's another one I guess: kids running around in their cub scout or girl scout uniforms.
There is no me. There is no you. There is all. There is no you. There is no me. And that is all. A profound acceptance of an enormous pageantry. A haunting certainty that the unifying principle of this universe is love. -- Propagandhi