The Andromeda Strain, Michael Crichton
Although I was familiar with the film I wasn't sure what to expect from the book. I wasn't even sure which came first, it was the book. It was readable but it had an unusual style. Alongside a typical third-person story story are extracts from "military documents", "scientific reports", and comments on the mistakes that are made. It's all tied together as a "report" into the incident.
