This was a book published in the 70s by DEC. I vividly remember at either the very beginning or the very end of the book there was a section on how to send submissions for consideration in future editions, complete with instructions on how to properly pack oiled teletype tape for shipping. :)
I found a copy of one of the editions of this book in my parent's book stash in the 80s some time after I got a C128. Up until then the C128 had spent most of it's time in C64 emulation mode alternately running a BBS, downloading cracked games while taking some liberties with the telephone system, or playing those games. Starting on that book put me on the path of teaching myself to program.
If the OP is looking for something that changes philosophical outlook, or something that might be relevant today, then I probably disappoint. However in taking the question literally, I'd guess this book set me on the path to the life I live today more than any other single book.