This chair had the top section of the arm removed by Jacob_M on instructables.com. Then he cut out a hole beneath the arm to reveal a large secret compartment inside. This doesn’t work on all couches, but some are waiting for someone to get the jigsaw...
This spark plug from Zemnesia seems to target a specific niche of people. If you have a shop or garage, or work on cars, you may be able to use this to store/transport valuables out of site.
This leather belt from Etsy includes a belt buckle with a secret compartment big enough for stashing cash, earplugs, gum, condoms or other small necessities on the go.
This ottoman/bench from Meijer conceals a locking internal cabinet that can store up to 5 long guns. The cabinet is lined with soft fabric and includes a removable tray for ammunition and handguns.
These systems from TV Coverups lift a picture, mirror or painting up to reveal your TV display behind it. Displays can be recessed or surface mounted. Sizes vary and they can be custom made to fit your needs.