A conjoined collection of safes that are made of thick lexan and wire-mesh smart glass. Normally, they're powered-down, as it were, and the glass is opaque. Each safe has a combination tumbler on it.
When someone attempts to break into the safe, and tumbles through an incorrect combination on any
one of the tumblers, the glass becomes clear. Thus, the burglar can actually see which of the safes they wish to really get into. This is where the fun really starts. They'll attempt to check all of the safes, probably, and pick each one.
The joke is on them, however - the combination is actually operated by setting a single number on several different tumblers. A closed-circuit system then deactivates the appropriate locks and opens the safe doors.
Just for fun, one of the safes will have an easily-visible "I agree not to press charges" sheet signed by the homeowner.
When the safes are opened, the system can be programmed by the owner to be as simple or complex as he or she likes, through a USB port inside one of the safes and an accompanying software package.
Inspired by "Lots of Safes" (link) by [Zircon].