Hansel and Gretel. The Brothers Grimm. Illustrated by Lisbeth Zwerger. 1979.
Austrian illustrator Lisbeth Zwerger won the prestigious Hans Christian Andersen medal in 1990, the highest honour that can be awarded a children's book illustrator for a body of work. A simple Google-image search on her name will show you why. Her art is diverse, from dark to whimsical, she projects atmosphere deftly, and her style is unique despite being rich in influences. I particularly like the way she plays with space on the page--there is a balance to everything she does. She works mainly with folklore, bringing her own vision to classic tales and fables, but she has also illustrated canonical children's texts, such as Alice in Wonderland and The Wizard of Oz.
I have chosen one of her earlier works, Hansel And Gretel, because I am drawn to her Rackham-esque darkness. I have also included an image here from The Little Mermaid because I want to give a sense of her artistic range... and I've included one from The Selfish Giant to demonstrate her skill with space and balance.