I have just finished Being No One: The Self-Model Theory of Subjectivity by Thomas Metzinger. It took me ten months, on and off, so finishing it feels like a Life Event. The book is 635 pages long and extremely technical; it's a difficult read, in other words, but I found it exhilaratingly difficult. And my picture of the human condition has been permanently changed, which is all you can really ask of a book. This change only amounts to a bunch of tweaks and polishes, admittedly, because I was already pretty sympathetic to the worldview expressed here, but they're tweaks and polishes at the deepest metaphysical levels. For those without any philosophical training, Metzinger has published a shorter, more accessible version called The Ego Tunnel. I haven't read that, so I can't authoritatively recommend it, but what I can recommend without reservation is Peter Watts' terrific SF novel Blindsight. That book is in some respects an 'adaptation' of Metzinger's theories, and I bought Being No One after finding it discussed in Blindsight's appendix, which is an agreeable route by which to arrive at a philosophy book.
I don't know that I have the mental resources at the moment to write anything substantive about Being No One, so I'll just finish with a short passage chosen almost at random from the many I highlighted. Consciousness is sometimes regarded as a sort of gift from God that allows human beings to appreciate the external world in all its plenitude; Joyce and Proust came to mind when I encountered this idea that consciousness is, on the contrary, a way of narrowing the external world to a manageable and unambiguous sliver.
"One main function of conscious experience may be to construct a final phase in a process of reducing information, data, and uncertainty originating in the buzzing, blooming confusion of the external world. As recent research into bistable phenomena (e.g., see Leopold and Logothetis 1999) has vividly demonstrated, if two incompatible interpretations of a situation are given through the sensory modules, then only one at a time can be consciously experienced. The generation of a single and coherent world-model, therefore, is a strategy to achieve a reduction of ambiguity. At the same time, this leads to a reduction of data: the amount of information directly available to the system, for example, for selection of motor processes or the deliberate guiding of attention, is being minimized and thereby, for all mechanisms operating on the phenomenal world-model, the computational load is reduced."