Code Complete (Second Edition) by Steve McConnell
This is the second edition of the classic 'software construction' guide. It has been updated to bring it into line with current developments in the software construction arena.

It serves as a great reference, with some very easily understood topics, some excellent insights into the reasoning behind various aspects of coding, many a 'best practice' and numerous checklists. Print them out, lay them on your desk and cover it all with a desk sized sheet of Perspex.

Not so much of a read from start to finish book, more of a jump around various chapters and then keep it on hand to refer to on a daily basis.

Smart and Gets Things Done by Joel Spolsky
This is in the format of a pocket book and contains a whole bunch of stuff that can be read on Joel's blog, I expected a lot more from it.

That said it is a good reference to all the hiring related topic / knowledge. It follows Joel's well known 'give them all private offices with a view of paradise and pay them just ever so slightly more than the annual cost of running the international space station' philosophy.

Just after buying this (July 2007) I had an opening in the development team at C2C (job advert here), so pretty opportune and a great refresher before the interview and hiring tedium hell process.