i actually have somewhere a complete list of all the ff super bossess (though it didnt include optional bossess who WERE WEAKER then the last boss or any thing in ffIII since i havent beat it)

ff1-IX had a total of EIGHT super bossess, being(SPOILER)Warmech, Omega, Shinryu, Emerald Weapon,Ruby Weapon,Omega Weapon, Ultima Weapon and Ozma

after that it just goes crazy. ffX had about 46 super bossess while ffX-2 had about 15 or so. hopefully ffXII will turn it up even more.