The stuff about business and tech companies (the clacks) in Going Postal novel is more relevant now than it was in 2003 when it was published. As is the stuff about inclusion amongst different types of beings.
It’s a remarkably prescient book, given it's 20 years old.
It’s always been my favourite Discworld book. More so after the current reread.
Highly recommended. You don’t need to have read any other Discworld books to read it. It’s a good entry point.