NES: If we are going by literally on the nes. Ive only played 3 but otherwise...
Best: FF2. Wrst:FF1

Snes: Best: FFV Worst: FFIV

PsX Best: ffix worst FFVIII

Ps2: Best FFXII Worst FFX-2 So far.

Current: best: FF XIV. Worst LR FFXIII (used to be my fav of the xiii but.. no anymore)