We have hardwood floors, which aren't too cold and hold up pretty well w/dogs. There ARE scratches on the floor {but remember, I have lots of kids too, and they all have friends!} , but they're not really visible – our floors are about four yrs old and still shine beatifully, and they are very easy to keep clean. I love them.
We have tile in the kitchen and frankly, it is harder to keep looking nice and clean. Of course, ours our lighter in color, but I often see little footprints on it!
My bedroom floor is bamboo, and I try not to allow the dogs in there too often because the paperwork we got w/the flooring stated that it scratches easily. It's only about one year old and still looks new, but like I said we don't let the dogs in that room often. Also, the paperwork we got recommended only dust mopping -- no liquid cleaners at all. I need to be able to feel like I can really scrub the heavy traffic floors once in a while, so I'd never put it in the main part of my home.