Weinberg's "Lectures on QM" is an excellent, graduate level text on the quantum mechanics that, among other things, will prepare you for studying quantum field theory. The book is authoritative, and very clearly written. Some highlights: (1)  He includes some fascinating topics not easily found in other QM texts. These include a very clear discussion of the Heisenberg 'matrix mechanics method' at the beginning of the book, and Pauli's algebraic solution of the energy levels of the hydrogen atom. (2) The book is very valuable for allowing one to see how Weinberg approaches and formulates solutions for standard introductory quantum mechanical problems (the 'easy' problems). (3) Weinberg's discussion of the interpretations of QM is the clearest and most detailed I have seen anywhere. (4) His chapter on isospin symmetry and its generalization is a very clear introduction to the use of symmetry in QFT. Also, his discussion of symmetry breaking in non-relativistic vs. relativistic cases is quite nice.