Both are really great games. Final Fantasy 4 has a better story. But Final Fantasy 3 is better because of the jobs.
IV is much better. I preferred the set jobs really. Story wise there is no contest. Also, III's final dungeon was just ridiculous.
Final Fantasy 4 on GBA was better than on the DS. But still a great game on DS. Also in Final Fantasy 3 if you died at the final boss you had to go through the whole dungeon again. Which is so stupid.
THE DAMNED MAIN REASON WHY I PLAYED THE GAME TWICE HOPING FOR A MIRACLE, AND ENDED UP DYING EXACTLY AT THE SAME FRIGGIN LAST BOSS!! But I still preferred this game Oddball me