Formerly known as Wordstock, this one-day celebration isn't some booth-filled convention where you wait in line to get a picture with George R. R. Martin. This is a book festival, where attendees excitedly pingpong across the South Park Blocks to listen to writers like Ta-Nehisi Coates and Tom Perrotta talk about their latest works and whims. There are also writers' workshops—and yes, a splendid book fair.