Subject: Linear Algebra
Recommendation: Introduction to Linear Algebra by Gilbert Strang
Reason: Strang presents the subject so clearly and intuitively that you feel like an expert on the subject after reading each chapter. It is by the far the best textbook I have encountered.
He is also an excellent teacher and offers the lecture notes to the corresponding MIT class online.
Strang's hand-wavy teaching style in my opinion kinda falls apart towards the later part of the course. I feel like the whole second half is kinda half baked. I didn't come away really having a good intuitive understanding of what the SVD was or why I should care about eigenvalues. I definitely think it's a good place to start though, but if you want something a little more organized I'd really recommend.
It's very clearly written and all the proofs are not too long nor too short. It pretty quickly goes through all the stuff Strang covers and moves on to more difficult things.
Thank you for that recommendation; I had not heard about the book before.
An extra nice thing: the book's chapters are available for free --- for downloading and viewing, and not for other uses --- from the book's website: http://matrixanalysis.com
Strang is not adequate for someone looking for a rigorous presentation of linear algebra. Axler's Linear Algebra Done Right, and Halmos's (older) Finite-Dimensional Vector Spaces are superior in rigor.
Book: http://www.amazon.com/Introduction-Linear-Algebra-Fourth-Edi...
Lecture: http://ocw.mit.edu/courses/mathematics/18-06-linear-algebra-...