Perfect

Perfect is a term used to describe a weapon or weapon upgrade that has the maximum bonuses available for its type. For example, a "Hammer Grip of Fortitude" providing a +30 bonus to health would be considered perfect, while one providing +25 or +29 would not. Also, a weapon with the maximum damage possible for that type is generally considered perfect. If someone refers to their perfect weapon, it is implied that the weapon has maximum damage, as well as at least one weapon modifier with its respective maximum bonus. (eg. Damage +15% while Health is above 50%)

Most of the time perfect refers to all mods being "max" or perfect and generally means a Damage +15% while Health is above 50%, Health +30, and 20% Armor Penetration. (20% Chance) It is noted many refer to weapons as the most "perfect" weapon in the game. This is purely subjective, however.