Another interesting item at GTS was a puzzle adventure book by Mike Selinker of Paizo publishing.

The book's pages aren't in the correct order, so, in order to complete the story, you'll need to weave your way through it. But, this isn't a choose your own adventure book, oh-no. Instead, you'll need to solve a series of increasingly difficult puzzles in order to put the story in the right order. It's a story and a series of games all in one.