I believe that would be the relatively new armour from player-owned ports. For magic, that would be the Sea Singer's Robes. There are two versions: the untradeable one, which you have to make yourself in your player-owned port, and the tradeable one, which you can buy. The untradeable one is better than the tradeable one. Note that the tradeable armour from player-owned ports costs many millions, while for the untradeable one it will take you months to get all the pieces.
Mystic armour is good and cheap
The Best magic armour in the game has to be Full Ahrims, since it gives great magic bonuses plus added defence on top of it.
The best Armour for Free-to-play characters are: Corrupt dragon - Melee Green D'hide - Ranged Combat Robes - Magic
Magic is influenced by dozens of pieces of armour, amulets, rings, and potions.
The best armour to wear depends on the combat style you're using. If using melee, Dragon armour is the best, Black dragonhide armour is the best for ranged, and Grifolic armour is the best for magic. Using the wrong style armour for the wrong class will lower your accuracy.
Usually dragonhide or just take your armour off
bronze armour with a bronze square shield is obviously the best armour in runescape not even bandos can beat bronze.
Answer: none, all armour has to have magic weaknesses. Answer: Taking off your armour is better than keeping it on, if you are being attacked by magic. There are other types of clothing (not labelled as "armour") which do provide magical protection, for example, the wizard hat, or the wizard robe.
Proselyte armour.
Black d'hide if your a member, green d'hide if you're not.
Ardourgne
Dharoks and Veracs