Ranged armor is good against magic but weak to melee damage. It is specially done for the Rangers in the game.
Leather Armor – Available as Leather, Hardened, and Studded, this is the only ranged armor available in the free edition. It’s a weaker armor but can be improved upon with the studs and hardening. It has a little defense against magic rating and is more resistant to crush attacks. It's one of the more flexible armor types.
Snakeskin – This is available in the members edition of the game. It’s a popular set that is close to a full set of armor in the game. It requires 30 ranged and 30 defense to wear.
Spined Armor – This is another members only armor set that requires 40 ranged and 40 defense to wear. It is a nice medium level armor and good against crush attacks. Dagannoth beasts on the Waterbirth Island can be harvested for parts for this set.
Dragonhide Armor – This is found in Green, blue, red, and black types and it’s a much stronger armor. It’s a good defense against magic but will aggravate the players trying to use spells as it may infere with that ability. It is a craftable item and one of the most popular armor sets in the game. It is a members only set.
Karil's Armor – Found in the members game only, it is received in the Barrows minigame. If you get the armor and the weapon you will get a set effect as well. It is a three piece set of armor that needs 70 ranged and 70 defense to wear.
Third Age Armor – Not in the free game, third age armor is rare and may be a level 3 treasure trail reward. It is a four piece set and it requires 65 ranged and 40 defense to wear.
Armadyl's Armor – The single most desirable armor in the game for rangers, it’s a members only item. It is a three piece set that requires 70 ranged and 70 defense to wear. It is a drop from the Aviantese in the God Wars Dungeon.
Just remember that in the game, you get what you can out of it. To get the rarest of the rare armor you are going to have to go into the minigames and into the really bad dungeons and seek it out, its not going to be a low level drop no matter how lucky you are.