I cannot recommend this book highly enough. It's got a lot of great insight into how to reason about low-level issues, but Abrash (who is now a programmer at Valve, I think; first in the credits for Portal 2) isn't just a cranky assmebly hacker. He recognizes when problems are better solved at a higher level, and tells the reader as much in several amusing chapters.

Also, the man's a fucking beast: http://www.mobygames.com/developer/sheet/view/developerId,21...