I read 11/22/63, A Game of Thrones, Turn of the Screw (The Haunting of Bly Manor), and Daisy Jones & the Six when I learned they were going to be turned into shows, but I read the books before the shows premiered.

I think the only book I've read after watching the TV adaptation is The Haunting of Hill House.

All other adaptations I've watched I had already read the books before I knew they were being turned into a TV show or I haven't read the books at all.