Oooh the WKB approximation :O I love this challenge already.
*nerd happiness* Quantum Theory :3
Also, may I suggest that @UndeadLover should read The Feynman Lectures on Physics, particularly volume 3 as that is the one that deals with the Quantum Theory. Another good ones, since it explains everything rather well and has examples is Quantum Mechanics, concepts and applications, by Nouredine.
Also, of course the classic; Modern Quantum Mechanics.
I also know quite a few good books on Quantum Computation, Quantum Field Theories, Matter Physics etc that you may like if you find that you liked these books.