Used these boxes to store books that we plan to resell next school season. You only assemble the boxes you need the rest remain flat until ready to fill (thus easy storage yet available when needed.) I like the uniformity and I can easily mark the contents on the outside of the box. And the price was right! Because they are cardboard they are not great for stacking heavy items.
I am using them to organize my current & previous year's income tax records. We itemize but I am still going to be able to fit more than one year in a box. Their size and shape allow them to store neatly on a shelf.