the first four games, i see like pairs. FF1 and 3 have a story that is really thin on the ground. the fun of these games is the battles and dungeons.

FF2's battle system is a bit weird... and FF4's is just too simple. but both have much more detailed and interesting stories than FF1 or 3. in fact quite a bit of FF4's story is based on FF2.

in order, i'd say each game improved on the last overall.