I'd also recommend (inter alia -- there's a lot of great works out there!) Friedman et al.'s Schemer books, Petzold's "Code" and "The Annotated Turing," McConnell's "Code Complete," Pierce's "Types and Programming Languages," and Warren's "Hacker's Delight."
Huge plus one for OS: Three Easy Pieces. It sticks in my memory forever and I just confirmed, I had a random question about "why" from part of that book in 2014 and emailed Remzi and within a few days had a very detailed response back. It was much appreciated because I can get hung up on little details that I can't explain and it can really create a wall for me, so thanks Remzi for being responsive to a learner!
Worth mentioning (I think it was elsewhere in the overall thread) CODE is getting a 2nd edition later this year. I've always meant to read the book but never did, so I'm planning on using the second edition as my excuse to finally do so.
