Twisty Little Passages is great.
Its author, Nick Montfort, also co-wrote Racing the Beam, a book about the Atari VCS/2600—and which is specifically thinking about it as a platform. It goes into the nitty gritty. It also thinks a lot about what it means to think about a platform as such—i.e., what do the specifics of the 2600 lead to when designing games? Its the first of a series of books about platforms (there's one about the Wii, the Amiga, Flash...: http://platformstudies.com/). It's the only one I've read (so far); I've been told it's the best.
The other coauthor, Ian Bogost, also wrote a book called How to Do Things with Videogames, which is also pretty good. It mixes in a bit of philosophy and big-picture thinking about videogames, although I suspect most of you would be pretty familiar with it.
All those books swing a little more academic, but not unbearably so.
Less academic is Anna Anthropy's Rise of the Videogame Zinesters: How Freaks, Normals, Amateurs, Artists, Dreamers, Drop-outs, Queers, Housewives, and People Like You Are Taking Back an Art Form, which was largely an exploration of Anthropy's work and an exhortation to, you know, go make video games! Which I nearly went and did, except I don't actually have the time to do that right now. I probably wouldn't make the same kinds of games that she makes. But that's OK! It was inspiring to read about her approach.