This  triangle-shaped shelving unit was very easy to assemble in less than 10 minutes.  As we were assembling it, we decided that it was a bit too high for the corner we were using it in, so we were able to simply leave out a level and make it into 3 shelves instead of 4 shelves.  If we move it to a different spot in the future, it will be easy to simply unscrew the supports and add the fourth shelf.  We use this shelf to hold a power bar, router, Ooma telephone unit, and phone, but it is attractive enough to use for displaying photographs or knick-knacks.

Pros: Easy to assemble; can set up as either 3 shelves or 4 shelves; attractive