'Jaws' from the Penguin Horror book series by Tom Lenartowicz I'm a big fan of minimal design for book covers. Most of the letters being underwater like a shark and the top of the 'A' being out like a fin is very clever and effective.
I like the overlapping and the layering of different opacities and coloured letters to create an image. Each booklet has a different colour scheme but they all use the same technique so work together nicely as a series. Bright colours used represent happiness, no dull colours