If you consider C to be language-agnostic, here are some gems. These are personal favorites as much for their excellent writing as for their content.
The Unix Programming Environment was published in 1984. I read it over 20 years later and was astonished at how well it had aged. For a technical book from the 80's, it is amazingly lucid and well-written. It pre-dates modern unix, so things have changed but much that goes unstated in newer books (for brevity) is explicit in UPE. (Plus, the history itself is illuminating.) It gave me a much deeper understanding of how programs actually run over computer hardware. Examples in C are old-school and take a bit of close reading but oh so rewarding. https://www.amazon.com/Unix-Programming-Environment-Prentice...
The Unix Programming Environment was published in 1984. I read it over 20 years later and was astonished at how well it had aged. For a technical book from the 80's, it is amazingly lucid and well-written. It pre-dates modern unix, so things have changed but much that goes unstated in newer books (for brevity) is explicit in UPE. (Plus, the history itself is illuminating.) It gave me a much deeper understanding of how programs actually run over computer hardware. Examples in C are old-school and take a bit of close reading but oh so rewarding. https://www.amazon.com/Unix-Programming-Environment-Prentice...
Mastering Algorithms in C. Another fantastically well-written book that shows (with practical examples) how to implement common algorithms. This is just such a great book! https://www.amazon.com/Mastering-Algorithms-Techniques-Sorti...
Also:
Code (Petzold). This one is truly language-agnostic. Others have mentioned it already. Can't recommend enough if you're iffy on the internals of computers and programming. https://www.amazon.com/Code-Language-Computer-Hardware-Softw...
Write Great Code (Volumes I and II). Randall Hyde's books are fantastic explications of the underlying computer operations. Examples are in assembly or pseudo-code but easy to understand. https://www.amazon.com/Write-Great-Code-Understanding-Machin...