If we're talking about FULL SETS... Guthans are used for Kings, Fight caves, and healing, so they are the most used ones making them the most expensive. Veracs have a good special, good for KQ. They also have a nice prayer bonus. Dharoks have a great special, they are good for strenght training. Torags... best defence bonus in-game, but the set effect and hammers _SUCK_, you never see anyone using full Torags, usually just plate and legs, sometimes helm. Ahrims have a great magic bonus making it the best mage set in-game, but with a very sucky set effect and staff. Like Torags, noone ever uses the full set. Karil is the best ranger set in-game, if you don't include the bow and effect. Like Torag and Ahrim, the set effect sucks... Well, you sometimes see someone with the bow, but it's not worth it for training or anything. Every set has it's pros and cons, it just depends on what you think "the best" means. :)