Sendak's books are notable because while they feature the usual protagonists of children's literature, the tone of the writing and the illustrations produce a darker undertone. The elements of magic and monsters (obvious or not) have shown up in my own art and writing time and again. There is also a sense of alone-ness, or the importance of making your own decisions that recurrs in all of Sendak's stories. I believe that Sendak's magical illustrations and the feeling of safety and assurance he creates while still populating his worlds with fantastic and sometimes fearsome creatures drew me to this subject matter in my own work.
Here is an interview with Sendak where he explains a little bit of his philosophies and inspiration.
NOW interview