Ask HN: What's the best book on quantum mechanics you've ever read?

I'd recommend Griffiths "Introduction to Quantum Mechanics". The writing style is informal enough that it's comfortable to read, but still had enough mathematical rigor to teach the material. It's certainly not a definitive reference, but I only reach for my other books after I've determined that it's not in Griffiths.

The Quark and the Jaguar by Murray Gell-Mann is a very idiosyncratic book, but with an interesting middle section on quantum mechanics.

If it's your first book on Quantum mechanics, I recommend: In search of schrodinger's cat

The Feynman Lectures on Physics - Vol III