It irks me that that model of Zidane is not how a PS1 would render him. That's either from a later release, a PS2 playing FFIX with smoothing enabled or an emulator....but that aside, FFVIII is a very similar leap from FFVII so I'd say that was comparatively a larger leap.
But as for my own contribution, I have no idea but do we consider "Mickey Mouse" a franchise? Because the leap from Castle Of Illusion to Mickey Mania on the Mega Drive was pretty huge, screenshots don't do justice to the jump, Castle of Illusion looks nice enough but Mickey Mania had large, detailed, amazingly well animated sprites based on actual Disney animation work. Along with all sorts of graphical effects such as pseudo 3D, transparencies, and possibly the only depiction of a dead Mickey Mouse.
