NY Times: What Gets Left Behind

What does get left behind? We hadn't really thought about it until we read What Gets Left Behind in Sunday's NY Times. The sellers of our apartment left an old armoire in our place, which we've snazzed up and put to good use. We left a microwave in our old apartment, which we know the new tenant ended up keeping and using.

There are some strange instances in the Times article, which is linked above, but it got us curious. What have you found left behind in your apartments? Or what have you left behind, and why?