Although I don't spend much time in there, our puppy "condo" is one of my favorite spaces. Max and Huckie dislike being in there by themselves (and Scout would complain SO MUCH), but it's nice for them to have a room in case a guest is uncomfortable around dogs, or they're wet, or got into something stinky.
I like the puppy-centric art and the family pictures and all that--but my favorite part is the old mat that says "Wipe Your Paws." And I like that it faces outwards as if reminding those of us visiting to be respectful of the puppies' high standards for cleanliness.
Pic: Max and Huckie pouting in their condo.