[skilesare]

All the things by Christopher Alexander(Start with timeless way...explore the pattern language...move on to Nature of order...then others.)

Zen and Lila by Pirsig

Beginning of Infinity by Deutsch.

[talkingtab]

I second Christopher Alexander of "Patterns" fame, but his "Notes on the Synthesis of Form" tops my list and is available as a pdf.

[carapace]

Nature of Order is (IMO) probably one of the most important books of the twenty-first century.