Livre d'Or

I second this recommendation.

I was going to suggest The Curious Incident of the Dog in the Nightime which is mainstream lit, and a rather heartbreaking portrayal of an autistic child being let down by everyone in charge of his care. (or that's how I read it anyway). It's done very well and I found it very upsetting when I read it (when my autistic sib was a similar age to the protagonist) and I won't read it again but I'm kind of glad it exists and was popular.