These are the books I actually and personally use day in
and day out. As you can see, the list is surprisingly short.
Don't get abducted by aliens without them.
I'd also include Electrical Engineering Circuits by H. H. Skilling
and the Doubleday Science edition of Sandforth's Heat Engines,
but these are getting a tad hard to find.
Also see our Ed Abbey and Richard Feynman pages.