Mystic Quest for the SNES I'd recommend because it's simple, feeling like an intentional entry point for JRPGs.

Final Fantasy II (PSP), VI, X and XII are generally linear, so you shouldn't get too easily sidetracked. But if you feel adventurous and starts looking to see what the optionals are about, you can easily find the thread that leads to them, and you will soon learn these games get twice as big at least.

Persona 3, 4 and 5 are mostly independent of each other, so you can pick whichever you want, at most missing some discreet references. The spin-offs, however, require playing the games they are directly related to.

Parasite Eve is good and different from your usual JRPG, and you don't need to read the book it is a sequel to as a character explains the basic idea and the ending of the book at some point. But do mind it's an horror game.

Yet to play Sea of Stars, but apparently it's inspired by Chrono Trigger, so maybe worth taking a look?