This would depend upon where I was living at the time. For example, way, way back I lived in Madang in Papua-New Guinea. Hardwood floors definitely in such a place. Carpet would simply rot.
However, it a cold climate, where the winters are particularly cold, then a nice thick wool wall-to-wall, and perhaps even with a few rugs thrown on to of this, would be the way to go. The wall-to-wall would cut out any floor drafts.
But if you live in a moderate climate, then maybe hardwood floors in the busy, downstairs areas and carpet in the bedrooms.