Here is my favorite: Victor Prasolov, Problems and Theorems in Linear Algebra. Also avaliable in PDF. However, I wouldn't recommend this to any undergrad without olympiad background.

Generally, writing textbooks in form of problem compendiums is distinctive for Soviet mathematics. I could name some more books of this kind (such as one on Lie algebras), but unfortunately they are all in Russian and most have never been translated.

Here is my favorite: Victor Prasolov, Problems and Theorems in Linear Algebra. Also avaliable in PDF (mirror). However, I wouldn't recommend this to any undergrad without olympiad background.

Generally, writing textbooks in form of problem compendiums is distinctive for Soviet mathematics. I could name some more books of this kind (such as one on Lie algebras), but unfortunately they are all in Russian and most have never been translated.