Although A Deepness in the Sky was published in 1999, I didn’t get around to reading it until recently. Vernor Vinge deservedly won the Hugo Award for Best Novel for it.  The novel includes one of my favorite portrayals of an alien society, and also portrays a fascinating interstellar human culture.  (It is a prequel to the novel A Fire Upon the Deep, but it doesn’t really matter which order you read the two.)

You can buy it at Amazon or download the audio from Audible.