Best materials for Construction, Learning, Invaders, Energy Restoration, Production, Yielding, Attack and Defense

Also refer : http://fenrislegion.blogspot.in/2016/
In this post I'll cover the materials that are the best for each requirement.

Construction Equipments:
Bjorn's Helmet + 32%
Bjorn's Armor + 37.5%
Bjorn's Spear + 30%
Barbarian's Boots + 12%
Bjorn's goblet : 56%


Learning Equipments:
Sigurd's Hood +24%
Daredevil Armor + 25.5%
Harald's Blade + 33%
Scaled Shoes + 18% (Serpent)
Olaf's seal : 35%


Invaders: (Royal Guardsmen)
Guardsmen Helmet - +4.4% offense +4.4% defense +4.8% endurance
White robe - +4.4% offense + 4.8% endurance
Sword of vengeance - 4.4% offense + 4.4% defense
White boots - +4.4% offense +4.4% defense +4.8% endurance
Plated guantlet - +4.4% defense +4.8% endurance

Iron Production :
Brown Helmet - 75%  (Man eaters)
Bear coat - 67.5%
Bear Mace - 60%
No boots
Bear tooth : 67.5%

Hero experience : (Hun, Khazar)
Fur Hat - 40%
Steppe caftan -  30%
Khazar's bow - 22%
Wanderer's boots - 19.2%
Golden Bracelet - 20%

Energy restoration set:
Barbarian's helmet/Canis Bone : 15%
Barbarian's armor/Bear coat : 13.5%
Pack's claws : 12%
Barbarian boots/Beast Boots : 12%
Canis Eye - 13.5%

Yielding set:
Centurion's helmet : 10%
Centurion's armor - 9%
Centurion's dagger - 8%
Haakon's boots : +12%
Centurion's ring - 9%


I'll keep updating this post (Feel free to post a comment regarding feedback, missing/incorrect data.)