Squall
Squall has probably the most powerful limit breaks (Well Irvine's could rival Squall's for sure), not only that but their fun! I love keeping Squall's health in yellow, because not only does he do a powerful blow but it'fun to use the trigger when he does Renzokuken
Weapon - Limit Break
Revolver - Rough Divide
Sheer Trigger - Fated Circle
Cutting Trigger - None
Flame Saber - None
Twin Lance - Blasting Zone
Lionheart - Lionheart (But even if you didnt have the previous weapons you can still use thoses limit breaks, yay!)
*Note: You need the weapons magazine to have greater weapons or already have the items.
Rinoa
Rinoa's limit break is okay. She uses her dog Angelo (unless named otherwise, for fun me and my friend's sister called it titty once and couldnt stop laughing lol) ANYWAY, you have to the Pet Pals magazines and then set the limit break to learn in Rinoa's status screen.
Then she gets Angel Wing, after she becomes (erm won't say incase it spoils it for anyone heh), anyway she casts random spells, but they very strong.
Pet Mag. Vol.01
Angelo Rush Initial Attack
Angelo Cannon Initial Attack
Angelo Strike
Pet Mag Vol.02
Angelo Recover
Pet Mag Vol.03
Invisible Moon
Pet Pals Vol. 4
Angelo Reverse
Pet Mag Vol.05
Angelo Search
Pet Mag Vol.06
Wishing Star
Angel Wings acquired on the Third Disk
Irvine
Irvine's limit break is fantastic! You just need the right ammo, my fav being Armor Shot. You select the ammo you want to use then press the trigger button to shoot (best to it as fast as possible then you won't miss a second).
Bullet - Limits
Normal Ammo - Dark Shot
Flame Ammo - Flame Shot
Demolition Ammo - Canister Shot
Fast Ammo - Quick Shot
AP Ammo - Armor Shot
Pulse Ammo - Hyper Shot
Selphie
Very handy in a tight spot, her limit break is called slots, and basically press do over to scroll through the magic then select cast to cast the magic.
But the list can vary so i'll just down the ones i use.
Full Cure - Self explanatory really, fully cures all your party members HP.
Wall - Casts Reflect, Shell and Cure on allies.
Rapture - The enemy just sort of flies away lol
Aura - Allows character to use limit break without low HP
Quistis
Quistis' limit break is called blue magic and requires items for her to learn different skills. My fav is degenerator, which sort disintergrates an enemy or somethin, but you win the battle and thats what matters!
Item - Limit Break - Location
Laser Eye None (Default)
Spider Web - Ultra Waves - Fight caterpillarly enemy called Caterchipillar. near the Balamb Area
Corel Fragment - Electocute - Fight the Cockatrice near the Galbadia Area
Sharp Spike - Level ??? Death - Fight Tri-Face. Found in the Underground Facility
Black Hole - Degenerator - Fight the Gespers. Can only be fought in Laguna's Last scenario.
Water Crystal - Aqua Breath - Use Rare Item Ability and fight Fokaroru
Missle - Micro Missle - Use Bundoru and steal it from GIM52A in Missle Base
Mystery Fluid - Acid - Fight Gayla, near the Travia Snow area
Running Fire - Gatling Gun - Steal it from an enemy called SAM08G
Inferno Fang - Fire Breath - Steal it from the Ruby Dragons at Islands closest to Heaven/Hell
Marlboro's Tentacles - Bad Breath - Fight Morbors Island closest to Heaven/Hell
Laser Cannon - Homing Laser - Fight the robot boss in Lunatic Pandora
Whisper - White Wind - Steal it from the Adamantoise on the shores of Long Horn Island
Barrier - Mighty Guard - Steal it from Behemoths
Power Generator - Ray Bomb - Fight Iron Giants in Lunatic Pandora
Dark Matter - Shockwave Pulsar - Collect 100 Curse Spikes and then use Siren's Tools Menu Ability and make them into Dark Matter
Zell
Zell has probably the fun limit break, you get to input his moves. You collect Combat King magazines to learn more skills.
Attack - Button Input - Magazine
Punch Rush Circle, X - Initial Attack
Booya - Right, Left - Initial Attack
Heel Drop - Down, Up - Initial Attack
Mach Kick - Back, Back, Circle - Initial Attack
Dolphin Blow - L1, R1, L1, R1 - Combat King 001
Meteor Strike - Down, Circle, Up, Circle - Combat King 002
Burning Rave - Down, Down, Down, Down, Circle - Initial Attack
Meteor Barret - Up, X, Down, Triangle, Circle - Combat King 003
Different Beat - Triangle, Square, X, Circle, Up - Combat King 004
My Final Heaven - Up, Foward, Down, Back, Triangle - Combat King 005