SICP. I only read a little, but that little bit was enough for something to really click for me. When I dropped it, I felt like "Before, I knew some syntax, but now I actually understand how to put a program together".
Also, this is kind of cheating since I went through the "Nand 2 Tetris" video course, but there is a book that goes along with it, "The Elements of Computing Systems". The course really drove home for me the power of simple, well-designed layers in building complex systems, since the end goal of building a CPU from scratch sounded impossibly intimidating at the start but by the end I was comfortable in explaining every detail. I think it counts since the book covers the same material.
Also, this is kind of cheating since I went through the "Nand 2 Tetris" video course, but there is a book that goes along with it, "The Elements of Computing Systems". The course really drove home for me the power of simple, well-designed layers in building complex systems, since the end goal of building a CPU from scratch sounded impossibly intimidating at the start but by the end I was comfortable in explaining every detail. I think it counts since the book covers the same material.