The Mythical Man Month, The Pragmatic Programmer, Code Complete 2.
You will get a lot of people recommending The Art of Computer Programming. Ignore them. This series of books costs and absolute fortune and I guarantee you that less than one in every fifty people who recommend the books have actually read them. Yes, they are very well written and are a seminal piece of work. But TAoCP is also an extremely terse and dry read, and ultimately not particularly useful in many modern programming fields. If you plan to go into high level coding (like the majority of CS grads) then you won't get as much out of the book as those moving into the very low levels (systems programming, embedded devices) or academic fields.
Of course this is just my opinion. I haven't read all of TAoCP (tried, but failed, like most people who attempt these books).