Emblem Gear (WoW)  

The idea behind Emblem Gear, or Badge Gear as it used to be called during The Burning Crusade was to combat the perceived unfairness of random loot drop.

By making each boss drop a token and than letting player spend token to buy gear they wanted from certain npc, players would be ensured that they would eventually get something out of raiding or running 5-man instances. The idea was introduced with Badges of Justice in TBC, was extremely well received with the player base and has now become an integral part of the game.

Badge of Justice & The Burning Crusade

Badge of Justice would drop from boss fight in level 70 Heroic Instance has well as the raid boss in Karazhan. At the time, farming instance for Badges was seen as the best way to get ready for the raid scenes. At a later date, Blizzard released a new batch of Badge Gear which was way superior to what one could get from Instance or Karazhan, allowing people to get ready for much harder content much faster.

While Badges of Justice and their vendor are still available in the game to this day, those are now legacy content/item.

Emblem of Heroism

Emblem of Heroism is the first tier of token dropped in Wrath of the Lich King - it can be gotten from bosses in the level 80 Heroic instance or from any boss in the the normal version of Naxxramas, Vault of Archivon, Eye of the Eternety or the Obsidian Sanctum.