Best dog house in the world is a section of concrete sewer pipe. Doesn't rust, nice and cool in the summer, and in the winter you can close one end. It even comes in sizes for different sized dogs.
Yep, I've seen those too.
But those are advanced ones here in my neck of the woods. Small pickup truck campers, a blue plastic bucket, and those white, 20 gallon buckets serve as doghouses here for a lot of dog "enthusiasts."