I’m much the same as @Zane - lots of bookcases, selection of prints and originals from artists and galleries here and there. We also have a couple of line and wash sketches of my own and several paintings by my SO, a mounted deer skull, a green man sculpture and a couple of landscape photos of mine. Neither of us do family photos.
In the past, I have had: a large mirror that I turned into a clock, a banner from a Greenpeace group that I was involved with, a tapestry that I friend made for us, a macramé owl that I inherited, a couple of film posters and a bicycle.