Flight Dynamics Principles by MV Cook (great intro text)
Aircraft stability and control by Babister (written by and for TPs and FTEs)
Helicopter Test & Evaluation by AK Cooke & EWH Fitzpatrick (written by ETPS guys)
Aircraft Control & Simulation by Stevens & Lewis
Feedback Control of Dynamic Systems by Franklin, Powell et al.
Fundamentals of Aerodynamics by Anderson (the only text you'll need for all your aerodynamic needs)
pretty damn expensive though...