I only really like PS1 and 4. PS1 I think is still totally playable. It has some grind at the beginning, but that's it -- it's not constant like in a lot of oldschool RPGs. And while it isn't open-ended by any means, there is a degree of non-linearity/sequence breaking, and the game definitely encourages to figure stuff out on your own.
I don't really consider PS4 to be that old school at all, though, except in the graphics department, obvs. Honestly I think that PS4 and Chrono Trigger ended up being precursors to the direction RPGs went during the 32-bit era.
As for PSIII, I SORT OF like it, but the dungeons suck (they're just boring, which is an improvement over PS2 at least), but there's some major balance issues. On the other hand there's some fan made mod I remember playing that improved balance immensely.
PS2's just a grindfest and the dungeons are atrocious which is a shame because the world aesthetics are great and the story, despite being minimally told, totally works. Heard the remake was actually quite good, which would be awesome except SEGA forgets America exists.
Shining Force, on the other hand... only played the first one. Didn't like it. Battles take a long time to get going, and it's easy to lose later in the battles. Maps are big and you have a lot of dead-time where you're just moving guys around. Also you end up with a handful of over-leveled units and a bunch of useless dudes.