It depends on what You like most I think.

If you search for the strongest armour "protection-wise" it's best to compare all the equipment itmes the trader's sell, because I finisshed FoV and see all the best equipment by trader's, except some Set items (Dragon Wizard, Shadow Archer or Viper) you can find via exploring.
I myself look most to that kind of equipment that have a skill on them I wish to use or upgrade it via wearing it. In FoV I mostly go for the extra pounts in Way of the Ranger