I have trains--O scale/gauge, Large Scale, O tinplate, and Z scale--displayed in just about every room of my home except the bathrooms and kitchen. All are in glass- or acrylic-protected cases so absolutely no dusting is needed (I HATE dusting). I'll try to take some photos this coming weekend.
Since I live alone--really very alone now until I get a new pooch--I don't have to answer to anyone when it comes to how I "decorate" my home. One of the few advantages of being single.