I think GGSSAI is the best book I have read on SQL Server. I like Ken's approach, detailed in his foreword, of finding out what goes on behind the scenes to truly understand something.
It would be great for our industry if everyone had the desire for deep knowledge like this then, perhaps, we would see better, more performant applications out there.
Or maybe it just the way of the world - after all, you don't need to look under the hood to drive a car...
DB Ghost - Build, compare and synchronize from source control = Database Change Management for SQL Server