Just a note for the "Best Junctions" column: The number in parenthesis is the amount that stat will be increased when junctioning 100 spells to that junction.  If an Elem-Def junction is more than 100%, then that will absorb whatever percentage it is above 100.

 

Magic Description Best Junctions
Cure recovers a small amount of HP for one ally Vit (15), Spr (15)
Cura recovers a medium amount of HP for one ally Vit (28), Spr (28)
Curaga recovers a large amount of HP for one ally HP (2200), Vit (65), Spr (65)
Fire causes minor Fire elemental damage to one enemy Str (10), Mag (10), ElemD - Fire (50%)
Fira causes medium Fire elemental damage to one enemy Str (15), Mag (15), ElemD - Fire (80%)
Firaga causes major Fire elemental damage to one enemy Str (30), Mag (30), ElemD - Fire (150%)
Flare causes major non-elemental damage to one enemy HP (3200), Str (56), Mag (44), ElemD - Fire, Ice, Thunder (80%)
Blizzard causes minor Ice elemental damage to one enemy Str (10), Mag (10), ElemD - Ice (50%)
Blizzara causes medium Ice elemental damage to one enemy Str (15), Mag (15), ElemD - Ice (80%)
Blizzaga causes major Ice elemental damage to one enemy Str (30), Mag (30), ElemD - Ice (150%)
Thunder causes minor Thun elemental damage to one enemy Str (10), Mag (10), ElemD - Thun (50%)
Thundara causes medium Thun elemental damage to one enemy Str (15), Mag (15), ElemD - Thun (80%)
Thundaga causes major Thun elemental damage to one enemy Str (30), Mag (30), ElemD - Thun (150%)
Quake causes Earth elemental damage to all enemies Str (40), Mag (40), ElemD - Earth (200%), STD - Stop (100%)
Bio causes Poison elemental damage to one enemy and gives the Poison status effect Str (24), Mag (24), ElemA - Poison (100%), ElemD - Poison (150%)
Aero causes Wind elemental damage to one enemy Spd (20), Hit (22), ElemD - Wind (80%)
Tornado causes Wind elemental damage to all enemies HP (3000), Str (48), Mag (42), Hit (38), ElemA&D - Wind (100%)
Water causes Water elemental damage to one enemy Mag (44), ElemD - Water (150%)
Holy causes Holy elemental damage to one enemy HP (3800), Str (55), Mag (45), Spr (48), ElemD (200%), STD - Dth, Bio, Brsrk, Zmb, Slp, Doom, Cnfs, Drain (40%)
Life revives a fallen ally with 25% HP Vit (50), Spr (50), ElemD - all (30%)
Full-Life revives a fallen ally with full HP HP (4800), Vit (80), Spr (85), ElemD - all (40%)
Death attempts to instantly kill one enemy Spr (58), Luck (38), StA&D - Death (100%)
Zombie causes one enemy to be made undead Vit (24), StA&D - Zombie (100%)
Regen gives Regen status effect to one ally (recovers HP) HP (2600), Vit (70), Spr (60)
Float levitates one ally/enemy, immune to Earth Spd (16), Luck (20), ElemD - Earth (50%)
Scan see one enemy's vital statistics  
Demi reduces one enemy's HP by 1/4 Str (34), Mag (36)
Break non-elemental damage and petrifies one enemy Mag (34), Spr (35), ElemA&D - Stone (100%)
Haste speeds up ATB gauge for one ally/enemy Spd (50)
Slow slows down ATB gauge for one ally/enemy Spd (40), StA&D - Slow (100%)
Stop stops ATB gauge for one ally/enemy Spd (48), StA&D - Stop (100%)
Double can cast two of the same magic consecutively Hit (40)
Triple can cast three of the same magic consecutively Str (70), Mag (70), Spd (70), Hit (150)
Esuna removes negative status effects Vit (36), Spr (36) StD - all but Zombie and Death (20%)
Dispel removes positive status effects Spr (60), Vit (38), StD - Drain (50%)
Protect doubles physical defense for one ally Vit (40), ElemD - Fire, Ice, Thun (20%)
Shell doubles magic defense for one ally Spr (40), ElemD - all (20%)
Reflect reflects magic to opposing party Vit (46), Spr (72), StD - all but Death, Zombie, and Doom (25%)
Drain steals HP from one enemy and recovered by caster StA&D - Drain (100%)
Aura increases chance of limit breaks for one ally HP (3400), Str (70), Hit (50), Luck (40), StD - Doom (100%)
Blind causes Blind status effect for one enemy Hit (30), StA&D - Blind (100%)
Silence causes Silence status for one enemy StA&D - Silence (100%)
Berserk causes Berserk status for one enemy StA&D - Berserk (100%)
Sleep causes Sleep status for one enemy StA&D - Sleep (100%)
Confuse causes Confuse status for one enemy Mag (28), StA&D - Confuse (100%)
Pain causes Poison, Blind, and Silence statuses Mag (60), Spr (45), StA&D - Poison, Blind, Silence (100%)
Meltdown non-elemental damage and Vit 0 status (defense cut in half) Vit (80)
Meteor non-elemental damage to random enemies HP (4600), Str (75), Mag (52), ElemD - Earth, Wind (150%)
Ultima major non-elemental damage to all enemies HP (6000), Str (100), Vit (82), Mag (100), Spr (95), Eva (60), Luck (60), Spd (60), Hit (60), ElemD - all (100%)