I'd recommend Griffiths "Introduction to Quantum Mechanics". The writing style is informal enough that it's comfortable to read, but still had enough mathemati

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.