I'm not looking to gain any practical skills from these recommendations (ex: not "Clean Code", "The Pragmatic Programmer"). Last year I read through the two books in Fabien Sanglard's Game Engine Black Book series and would love to get my hands on more books like them. Books that focus on history, arcane details and secrets once thought lost to time. Sadly it appears I've already worked through Sanglard's entire bibliography. But I'm sure there's more stuff out there like it.