I certainly don't remember Anxious Hearts being used in a battle, it is a wonderful piece of music though.
Let's see here...
CT: Magus' Battle
Boss Battle 2
World Revolution
Last Battle
SD3:
Nuclear Fusion
Three of Darkside
Obsession
Frenzy
Faith Total Machine
Black Soup
High Tension Wire
The Sacrifice (all three parts, despite only 2 and 3 being played during battles, if I recall correctly).
FFI:
Normal battle music
FFIV:
Red Wings
Fight 2
Dancing Calobrena
Golbez's Theme (I remember it being played in a battle you can't control, but it still counts)
The Final Battle
FFV:
Battle With Gilgamesh
The Decisive Battle
FFVI:
The Decisive Battle
Grand Finale #2
The Fierce Battle
FFVII:
Still More Fighting
Aeris' Theme
J-E-N-O-V-A
Jenova Absolute
The Birth of a God
FFVIII:
Force Your Way
The Man With The Machine Gun
Premonition
Maybe I'm a Lion
The Extreme
FFIX:
Battle 2
Hunter's Chance
The Sword of Doubt
Protecting my Devotion
Dark Messenger
FFX:
Someday the Dream Will End (I'm not sure if this was played in a battle, for some reason I think it was)
Seymour Battle
Aeon Battle
Braska's Final Aeon
FFX-2:
YRP Battle Theme 1
Lunar:
Stand and Fight
Go Go Go!
Fighters (I think this is played during a battle)
Magical Weapon Nash (ditto above bracket)
(I used the SPC/PSF archives for the track names, so blame them if they're incorrect)