My favorite book is Douglas Adams’ Last Chance to See. He talks about it here [0] and IIRC he says it was his favorite book to write. Adams took a dark subject - endangered animals and our role in their extinction - and told a story that’s equally hilarious and hopeful.
It’s absolutely one of my favourite books too. His style of humour was a perfect dichotomy of reverent/irreverent that made him the perfect author for a book like this. Beautiful appreciation of the world meets shake-you-awake, perspective-bending humour.
[0]: https://m.youtube.com/watch?v=_ZG8HBuDjgc