If you're at all interested in visual / graphic design, I'd highly recommend picking up a copy of Edward Tufte's Visual Display of Quantitative Information. I just got done reading through it after having set it aside for awhile. Although very consise, it highlights features of great graphic design every designer should keep in mind. He wrote much of it with pre-computer era graphs in mind, but I found that it translated very well to web design and computer interfaces as well.
One of his main ideas is that great graphic design reveals the greatest number of ideas in the shortest time, with the least ink, in the smallest space. He provides examples for almost every point he's making so it's easy to see what exactly he means.
Even if you're not into graphic design, it looks pretty good on a coffee table.