The best armor will cover the wearer's body completely, providing maximum protection from swords, axes, spears, and other implements of destruction. The worst armor appears in Capcom classic Ghosts 'n Goblins.
Someone had to make armor for Ghost 'n Goblins' hero, and that someone was the most inept armor crafter in all the lands, crafting magnificent suits of shining metal that fall off at the slightest touch. Such an artisan would have made a killing in the medieval porn business, but alas.