[weichi]

I've read Griffiths, most of Shankar, some of Sakurai, and some of Feynman.

Of those, I would say Griffiths is the best option for someone with your background. It's short enough that you have some hope of going through the entire book, and it has you doing real calculations. The writing is good.

Shankar has lots of good stuff, but its 600+ pages long, so a bit overwhelming. I also found the explanations not as clear as in Griffiths.

The perspective in Feynman and Sakurai is quite different than in Griffiths, and it is possibly a better approach. But Sakurai is much more challenging than Griffiths and not nearly as well written. Feynman lacks the worked examples and exercises that Griffiths has, so is not (IMO) appropriate as your sole textbook, but definitely worth looking at for the different perspective. A text taking the Feynman (or Sakurai) approach, but at the length and level of Griffiths, would be valuable.

(I taught myself basic QM prior to going to grad school in physics, with a background similar to your, so I have some direct experience here. This was about 12 years ago. Perhaps there are better options now.)