I like how in entries #9, 10, and 14 that the design not only has the curvature of the spine, but also has the look of stones that tend to signify relaxation or something natural. The use of a single color in that shade, coupled with the design and the text font makes entry #9 stand out the most to me. In entry #17, I like the blending of the colors in the design and in the text. Plus, I like the contemporary look of the design.
Really like entry #42. Is it possible to see it a) all in one color, b) the spine all in the darker shade with the rest the same, c) more contrast between the different shades of blue. These would be separate entries and not all possibilities in one.