Ok so "Dirk Gently's Holistic Detective Agency" is one of my favorite Douglas Adams books. It is, like, mind-blowingly well-synchronized. It presents and illuminates a notion of consequence and order, without offering up a conspiracy: everything happens for a reason, but nobody has any clue what's going on.
I found out today that there's a TV show. And then I watched all eight episodes. That's what I did today.
And it fucking nails it.
There are details I remember from the book that aren't there, that make me think it probably doesn't map 1 to 1, though it's been a long time since I've read the book. But the spirit of the thing -- the disparate narratives converging, the strange powers, the dense and changing emotional relationships -- are all there. And it's funny. And it's moving. And it's renewed for a second season! (Don't worry, the plot resolves within the season.)