I explore the Rocky and Columbia mountains and icefields very often, so I have a nice array of very interesting pieces of geology and fossils in my house (including many precious gems from around the world, such as my 4' tall amethysts).

I also have a few small memorabilia from movie sets that have been set up in my area (for example, I have a small wooden stake with rope around it that was used as a TP stake in The Revenant (which I just went and saw this past weekend).

Other than that, I have a fair amount of artwork from all over (mostly street art that artist friends put on paper/canvas for me), and many pieces by my step-daughter (she's an artist in the Bay area).

Besides those (which are not in abundance), I don't have much stuff; I dislike clutter.