So freaking good! A literal encyclopedia of tacos (hence the name of the book) with tacos from all over Mexico. Every taco entry comes with an explanation of what it is, where it comes from, how it's normally made, the variations thereof, recipes on how to make your own, and a list of restaurants in Mexico that serve the best versions of the taco.
There's even a section in the back for taco "cousins", like enchiladas, quesadillas, and tamales. The book includes tons of recipes for tacos, the cousins, and enough salsas to fill up a hundred molcajetes.
I have only one gripe for this book: regardless of where a particular taco comes from (whether the coasts, up north, central Mexico, or the Yucatan Peninsula), most of the restaurants with the "best" versions of that taco seem to be on Mexico City? Come now.