I'd say FF2 takes the cake for being the worst one prior to FFX. And still to this day, it is IMO, the worst. It's a shame too, since I like some of the characters from FF2. But the game play of FF2 just BLOWS chunks IMO. I just could not get behind its cumbersome leveling system.
I'd take FF8 any day over FF2. --- "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn."