FF1: Some of the various challenges. I've never maxed out my parties level either.

FFII: Max out all Magic

FFIII: Fully -Equipped Onion Knights at Lv. 99.

FFIV: I've never obtained the Adamant Armor, Pink Tail, Rune Ax or Artemis Bow.

FFV: Never maxed out the party level.

FFVI: Never done a CES challenge or Natural Magic/No Esper challenge. I don't think I've ever beaten Siegfried in the arena but I have beaten Chupon. I also haven't fought Omega Weapon in FFVIAdvance

FFVII: I've never gotten the Parasol and I've never done some of the various challenges.

FFVIII: I've never modded my GFs, I've always used their natural abilities and never modded them to get stuff like Str +60% or such nonsense. I've never done some of the challenges either.

FFIX: Never done some of the challenges. I've never finished the Jump Rope Minigame or completed getting all the Tetra Master cards.

FFX: I've never completely unsealed Wakka's Ultimate weapon, and I've never completed the monster arena, modified the sphere board for perfect stats, and I've never had a character complete the Sphere Board.

FFXI: In MMO terms, I've barely played this game so yeah...

FFXII: I've never completed the Sky Pirates Den (only missing three), never obtained all of the best weapons, never maxed my party levels, never beat Omega Mk XII, and never completed the Beastiery.

FFXIII: Never got all the achievements which will pretty much cut this short of what I needed done.

FFXIV: Never played.