Fave books!

Sometime there are books like "Thoughts" by Giacomo Leopardi (surprisingly, not available on Amazon). Reading them is like sleepwalking into a cold shower bang in the middle of a wintry Arctic night. And now I cannot wait to get my hands on A Pattern Language : Towns, Buildings, Construction suggested by Srikanth. The reviews had me all excited till I looked at the price! Which reminds me...what is the "best" book that you have read outside your domain of work that influenced your thought? Put differently, which book unrelated to your discipline of work mattered a lot to you? I am looking for cross-disciplinary ideation rather than inspirational or self-management books!