Phaedrus

The book I've reread the most is The Odyssey. For a long time, I've read it once every year. Another book I've read many times is Eco's Foucault's Pendulum. I've read Asimov's cycle of Foundation many times. Don't know how many, actually. I've also read several times some philosophy classics, particularly Plato's Symposium, Phaedrus, Apology and Republic. Then there are many books that I've read at least twice, almost all considered classics (from 1984 to LoTR, Great expectations to Tom Sawyer, Crime and punishment to Twenty thousand leagues under the sea, etc).

It really depends on what you're looking for, but Philosophy is a field where one philosopher's work is built on top of the other's going all the way back to the ancient Greek's. Its important (I think anyways) to read the raw texts before you read philosophical commentary so that you have a chance to form your own opinions. That being said, here's some recommendations of mine that cover a breadth of philosophical subjects and time periods. Its always good to see someone else want to learn more philsophy, especially if its of their own volition. Plato. Strangely enough, Plato is probably one of the best introductions to philosophy, not only because he was one of the first whose writings survive to modern time, but also because its relatively simple to read and understand. Some of my personal favorite are 'The Apology', 'The Symposium', and 'The Phaedrus', and of course 'The Republic'. The weird thing with Plato is you'll never know how much of his writings are his thinking as opposed to Socrates teaching. I still reread Plato because the stories (most of his writing is in narrative form) are so damn entertaining.…

Being a programmer, you've probably felt the appeal of Platonism, so I'd recommend a couple of his dialogues: Phaedrus, Symposium, and the Republic (in order of length, short to long, since they are pretty dense). I'd also recommend reading the Republic last, so you can get over the misconceptions you were probably taught in high school. Allan Bloom's Closing of the American Mind is also very enlightening for a) understanding the goals of the enlightenment, and b) understanding the current state of our culture.