There are many, many origami cubes -- this is one of my favorites and is not, I think, widely known. It is larger than the waterbomb, with 36.5% more volume, and hides most of its structural parts on the inside. It can be folded in such a way that five of the faces will have no creases on them, making it a good vehicle for graphics or photos. And its crease pattern has a strange and interesting relationship with the number thirteen.
折り紙の幾何学 (Origami Geometry) by Kôdi Husimi and Mitsue Fushimi, 1979 and 1984. ISBN-13: 978-4535781399