My personal recommendations, updated (textbooks not included):
Computer Science
Barrons; Be Prepared for the Computer Science Exam in Java (Litvin). Barrons is very comprehensive, and Litvin is good for practice exams.
Calculus
Peterson's; Multiple-Choice & Free Response Questions in Preparation for the AP Calculus (AB or BC) Examination. Peterson's is extremely comprehensive, and you won't need it if you're a strong calc student. The latter is also good for practice exams.
Statistics
Barrons. I don't have any legitimate reason for choosing Barrons over any other book here. Brush up on your Greek though, because they use the standard variables, and if your teacher made up his own variables, then you'll get pretty confused.
US History
AMSCO; REA: Crash Course. AMSCO is good for semester-long studying, Crash Course is very concise but gives more pertinent information per page.
Economics PR. Just the general consensus at my school.
US Gov
CliffsAP. Good enough for me, the exam wasn't too hard.
Physics
5 Steps to a 5; past AP exams. 5 Steps is very easy to understand, and will help if you don't fully understand the concept. I've heard Barrons is difficult to use as a review tool if you're not a strong Physics student.
Environmental Science
Smartypants' Guide; Barrons. Smartypants' isn't universally available, so Barrons is the next best thing (I think).
Chemistry
5 Steps to a 5 or
PR. 5 Steps seems to work well for the sciences for me.
Biology
5 Steps to a 5 or Cliffs. Cliffs is good, but I've developed an affinity for 5 Steps
English Language
CliffsAP. Lots of practice, not much else to say.
English Literature
CliffsAP or Barrons. Though your grade really depends on how much you've done over the year.
Psychology
Barrons. Comprehensive - perfect for self-studying.
Spanish Language
N/A. You're beyond help, don't bother. You've got x amount of years of language to fall back on.