There are different stat affixes that affect the maximum stat attribute roll for each armor piece.
If we look at all the possible affixes for the Strength stat:
"Ruthless" (max +100 Vit and Str) and "of War" (max +200 Str, see affix Str 16 on "Strength [Amulet, Axe, Belt, Bow, Ceremonial Knife, Dagger, Fist Weapon, FollowerSpecial, Hand Crossbow, Mace, Mighty Weapon, Offhand, Shoulders, Spear, Sword, Wand]") are the best affixes, resulting in a total of 300 Strength and 100 Vitality on a perfect roll for a rare iLvl 63 shoulder.
330 Strength and 200 Vitality,
but a perfect Archon Spaulders of Vitality would roll for:
300 Strength and 330 Vitality.
However the maximum possible stat affix for Dexterity and Intelligence armor is +200 for their respective stats.
For Intelligence, it's "Illustrious" (max +100 Int and Vit) and "of Far Sight" (max +100 Int).
For Dexterity, it's "Valiant" (max +100 Dex and Vit) and "of Pain" (max +100 Int).
So it makes more sense for a Barbarian to craft Vitality shoulders over Strength shoulders, but for other classes sticking with their main stat is better:
330 [Main Stat] and 200 Vitality vs. 330 Vitality and 200 [Main Stat].
Which plan provides the most optimal stat distribution for each piece of armor (including amulets) for each class?