One of the greatest books on the history of the tabletop roleplaying hobby is by Jon Peterson. It is called Playing At The World.
Empire of Imagination is a biography of one of Dungeons&Dragons' founders, Gary Gygax.
The basic rules set to Dungeons & Dragons that Jon mentioned in the episode.
The Call of Cthulhu roleplaying game Tracy's been getting into of late. One of the great classics.
One of my enduring classics - Rolemaster.
The World of Darkness setting for those into contemporary supernatural/monster stories.
Jon's favorite RPG these days is Numenera. It's character creation system will be discussed in episodes to come.
We discussed our great experience playing Hillfolk, which you can check out at the link.