Zapdos' Hidden Ability is Static.
Articuno's Hidden Ability is Snow Cloak.
Moltres' Hidden Ability is Flame Body.
Mewtwo's Hidden Ability is Unnerve. (available)
Mew does not have a Hidden Ability.
Raikou's Hidden Ability is Volt Absorb.
Entei's Hidden Ability is Flash Fire.
Suicune's Hidden Ability is Water Absorb.
Lugia's Hidden Ability is Multiscale. (available)
Ho-oh's Hidden Ability is Regenerator. (available)
Celebi does not have a Hidden Ability.
Regice's Hidden Ability is Ice Body.
Regirock's Hidden Ability is Sturdy.
Registeel's Hidden Ability is Light Metal.
Latios and Latias do not have Hidden Abilities
Kyogre, Groudon and Rayquaza do not have Hidden Abilites
Jirachi and Deoxys do not have Hidden Abilites
Uxie, Mesprit and Azelf do not have Hidden Abilities
Dialga, Palkia and Giratina's Hidden Abilities are Telepathy. (available)
Giratina's Origin Forme's Hidden Ability is Levitate. (available)
Cresselia and Darkrai do not have Hidden Abilities.
Manaphy does not have a Hidden Ability.
Heatran's Hidden Ability is Flame Body.
Regigigas does not have a Hidden Ability.
Shaymin's Formes do not have a Hidden Ability.
(Obviously) Arceus does not have a Hidden Ability.
Victini does not have a Hidden Ability.
Cobalion, Terrakion and Virizion do not have Hidden Abilites.
Tornadus and Thundurus' Hidden Abilities are Defiant. (available)
Landorus' Hidden Ability is Sheer Force. (not available, unlike the other trio members)
Reshiram and Zekrom don't have Hidden Abilities.
Keldeo, Meloetta and Genesect don't have Hidden Abilities.
Xerneas, Yveltal and Zygarde don't have Hidden Abilities.
FINALLY FINISHED. xD
Hope I helped. :)
Source, Serebii and Once's answer.
