I just finished reading The Speed of Dark by Elizabeth Moon (an author with an autistic son). It offers a good depiction of a character on the spectrum, Lou Arrendale. Across many chapters, the reader rides along inside Lou’s head as he puzzles through the many (legitimately!) confusing things about human culture. In particular, Moon does a good job highlighting situations where poor Lou has been chastised his whole life to avoid doing things that neurotypical folks routinely do without thinking.
There’s some psychological tension as the characters grapple with the prospect of an experimental treatment that can “cure” their autism.
This is a good read for anyone who wants to better understand one particular point on the spectrum, but the book falls short in showing more than just a narrow type of character. All the autistic characters in the book are pretty interchangeable.