There are four different levels of limit breaks, two on each of the first three levels and one level four limit break.  In order to get the second break on a level, you need to use their first break on that level 10, 8, and 6 times respectively for the first three levels.  To gain the first break of levels 2 and 3, that character must kill 80 enemies to get the next break.  As for the level 4 break, you must first find the item manual for the break and also have the six breaks prior to it.
Cloud Strife Level 1, break 1: Braver - dashes forward and slashes one opponent Level 1, break 2: Cross Slash - slashes an opponent three times Level 2, break 1: Blade Beam - a wave of energy is fired at an enemy and smaller waves bounce to the others Level 2, break 2: Climhazzard - a jumping upward-slash into an enemy Level 3, break 1: Meteorain - a shower of meteors hit all enemies four times Level 3, break 2: Finishing Touch - fires a tornado and kills weaker enemies, stronger ones drop for big damage Level 4: Omnislash - sweet combo of 15 slashes on random targets Omnislash is found at the Battle Square and can be "bought" for 32,000BP on disk 2 or 3 (64,000 on disk 1) Aeris Gainsborough Level 1, break 1: Healing Wind - restores a big chunk of HP to all allies Level 1, break 2: Seal Evil - casts stop and silence on all enemies Level 2, break 1: Breath of Earth - cures status ailments of all allies Level 2, break 2: Fury Brand - maxes out the other two characters' limit bars Level 3, break 1: Planet Protector - temporary invincibility for all allies Level 3, break 2: Pulse of Life - status ailments are cured and all HP and MP recovered for all allies Level 4: Great Gospel - HP and MP completely restored and temporary invincibility for all allies Get 1xx battles won (where the xx represents two digits that are the same) and go to the sleeping man in the cave south of Midgar.  He'll give you the Mythril that you take to the blacksmith near the Gold Saucer and you'll find the Great Gospel. Barret Wallace Level 1, break 1: Big Shot - shoots a big fireball at an enemy Level 1, break 2: Mind Blow - shoots a fireball that drains the MP of an enemy Level 2, break 1: Grenade - fires a huge explosion that damages all enemies Level 2, break 2: Hammer Blow - dashes forward and punches for either no damage or instant kill Level 3, break 1: Satellite Beam - satellites rain down with laser to fry the enemies Level 3, break 2: Ungermax - fires constantly at all enemies with his arm Level 4 - Catastrophe - fires a big yellow beam at all enemies for ten hits Catastrophe is found from a lady in North Corel after the train quest (Barret should be in your party). Cait Sith Cait Sith actually only has two limit breaks.  I don't know why, but I never really used him enough to care... Level 1, break 1: Dice - total of dice thrown determines damage done, also the first digit in Cait Sith's level determines the number of dice thrown Level 2, break 1: Slot - slot machine appears, and different results occur from different selections: 3 bars - calls a summoned monster at random 3 crowns - 6 toy soldiers appear and fire at enemies 3 stars - moogle appears to refill all allies' HP and MP 3 hearts - all allies have 100% hit rate for the rest of the battle 3 moogles - Cait grows to 9999HP and 999MP and has stronger attacks as allies disappear.  When the battle ends, all allies have one-third the HP and MP they had.  This won't work with less than two other allies. 3 faces - all enemies facing you are instantly killed Face, Face, Bar - all allies instantly killed (cannot be prevented) other combinations cause physical damage to the enemy Cid Highwind Level 1, break 1: Boost Jump - jump-slashes at one enemy Level 1, break 2: Dynamite - lights a stick of dynamite with his cigarette to toss to the enemies Level 2, break 1: Hyper Jump - much like a dragoon's jump attack, but causes damage to all enemies Level 2, break 2: Dragon - HP and MP are stolen from an enemy and given to Cid Level 3, break 1: Dragon Dive - jump attack for six hits Level 3, break 2: Big Brawl - attack for eight hits Level 4: Highwind - barrage of missiles strike all enemies from the Highwind Highwind is found in the sunken Gelnika plane Red XIII Level 1, break 1: Sled Fang - turns himself into a fire arrow and dashes through an enemy Level 1, break 2: Lunatic Howl - casts Haste on all allies Level 2, break 1: Blood Fang - same as Sled Fang but also absorbs some HP and MP Level 2, break 2: Stardust Rain - meteorite shower hits enemies total of 12 times Level 3, break 1: Howling Moon - casts Berserk and Haste on Red Level 3, break 2: Earth Rave - attacks enemies for five hits of physical and fire elemental damage Level 4: Cosmo Memory - a flare of fire damages all enemies Cosmo Memory is found by defeating the boss in the safe in the Nibelheim mansion (see Hints&Tips) Tifa Lockheart Tifa's breaks work in that a slot comes up and each slot represents a move in the series of breaks.  You can either get "Miss" which will miss the enemy, "Hit" which will hit for regular damage, or "Yeah!" which will hit for critical damage.  Each successive attack is on a random target. Level 1, break 1: Beat Rush - quick combination of punches Level 1, break 2: Somersault - somersault kick Level 2, break 1: Waterkick - a sweep kick hitting for water damage Level 2, break 2: Meteodrive - a back suplex Level 3, break 1: Dolphin Blow - an uppercut with a dolphin jumping out of rising water Level 3, break 2: Meteor Strike - a jumping body slam Level 4: Final Heaven - finishes off with a huge exploding attack Final Heaven is found at Tifa's Piano by playing the tune she was taught (see Hints&Tips) Vincent Valentine During all of Vincent's breaks, his HP doubles and will uncontrollably perform one of his two attacks each turn. Level 1: Galiant Beast - claws and bites enemies or tosses orbs for ice/lightning damage Level 2: Death Gigas - punches one enemy or fires lightning at all enemies Level 3: Hell Mask - attacks five times with a saw or casts silence, sleep, toad, and causes poison damage Level 4: Chaos - Chaos Saber - attacks all with his wings or - Satan Slam - instant death and special damage to any survivors Once you have the sub, or a colored chocobo (except blue), go to the waterfall and enter it from the left side with Vincent in your party.  Do so once on disk 2 and again on disk 3 and you'll Chaos from the girl you meet. Yuffie Kirasagi Level 1, break 1: Greased Lightning - slashes for physical damage Level 1, break 2: Clear Tranquil - regains some HP for all allies Level 2, break 1: Landscaper - blast waves sent to enemy causing earth damage Level 2, break 2: Bloodfest - hits all enemies ten times total Level 3, break 1: Gauntlet - hits all enemies for special damage Level 3, break 2: Doom of the Living - strikes random enemies for total of 15 hits Level 4: All Creation - huge white beam that causes critical damage to all enemies All Creation is found by defeating the five bosses in the pagoda in Wutai.