X-link to the DRM-free thread for a non-fiction Bundle of Holding:
Designers, Dragons, and More consists entirely of non-fiction about the history and design of RPGs and other games. There's a substantial 4-volume history covering Dungeons and Dragons and its assorted imitators, as well as the surrounding industries and culture which developed around them, another separate history covering GenCon, the decades-old largest RPG convention in North America, and a couple of books with top game designers discussing the design appeal of their favourite hobby and family games.