I love everything by Richard Hamming. They're soaked with the enormous practical experience/expertise he has with what he writes about. They're not just about applied maths, but about the range of problems you run into when you try to apply them e.g.
Numerical Methods for Scientists and Engineers (1962)
Introduction To Applied Numerical Analysis (1971)
Digital Filters (1977)
Methods of Mathematics Applied to Calculus, Probability, and Statistics (1985)