Dragon equipment

Dragon equipment is the best non-degradable metal armour in the game, but the second most powerful armour in Project RS06, falling right behind Barrows. Dragon armour is gained by drops from killing NPCs. Most of the weapons require a quest to be competed before it can be equipped. The only armor that requires a quest is the Dragon sq shield.

Dragon armour
If you cannot afford dragon armour, Rune equipment is a good option as rune is much less rare and therefore cheaper.