Here is a list of things that I tend to hoard (where I define hoard as "keep more (or longer than) needed, or conserve or manage more than the effort involved warrants"):
* Alaska license plates (I had to get the obvious one out of the way first)
* books and magazines
* cardboard boxes
* coins
* computers and peripherals
* computer adapters, cords and computer-related tools
* dowls, rods, tubes
* ID cards
* movie stubs
* paper
* pens and pencils
* plane tickets
* twist ties
* water
... and here are the things that I think that my wife hoards:
* books and magazines
* candles
* checks
* coffee cups
* cookbooks
* glass jars
* greeting cards received
* leftovers
* toiletries
Obviously, we have many bookshelves.