Primary

 Intelligence
 Strength
 Agility

Damage

 Physical Damage
 Elemental Damage
 Melee Damage
 Ranged Damage
 Fire Damage
 Ice Damage
 Light Damage
 Critical Damage
 Armor Penetration

Defensive

 Health
 Mana
 Armor
 Resistance
 Dodge
 Tenacity
 Life Steal
 Mana Steal
 Spell Vamp

Miscellaneous

 Move Speed
 Attack Speed
 Projectile Speed
 Cast Rate
 Jump Force
 Range
 Melee Range

Attack Speed

Attack Speed represents how quickly basic attacks happen in succession. Attack Speed increases as  Agility increases. Attack Speed is a useful to all Classes that prefer basic attacks, including the Warrior, Hunter, and Rogue.

Attack Speed can be reduced by  Slow.