I did all the Clan Centurio Hunts and most of the Elite Marks before taking on the final bosses, around level 60.

Now that I've beaten the game, I've gone back to an earlier save and gotten Ultima and (just today) Zodiark. I'm up to level 80 now. Next up is the Phon Coast Hunts, Omega, and Pharos Subterra. I'll save Yiazmat for last.

I find the game enjoyable except for the way you get treasure randomly from chests (the way the Zodiac Spear chest was handled was simply awful) and the way the automap is useless in the dungeons you need them the most.