I will be updating this list !!!
I do not know the books every (Java (Web)) developer should read. This is more like Books I would recommend and that I learned a lot from.
The Elements of Computing Systems: Building a Modern Computer from First Principles
A must read.. Can be bought from here.
I would recommend watching this as well:
Look how happy I am when I am near this book:
The Computer Programme
Well ok this one is not a book (no shit..) but a documentary. I would highly recommend it. Here is the wikipedia link about it. And here is a YouTube link to the series. Enjoy!