The The Taken King Add-on for Destiny has 10 achievements worth 250 gamerscore.
Complete "The Court of Oryx" quest.
Complete "The Wolves of Mars" quest.
Complete "The Sunbreakers' Challenge" quest.
Complete "The Stormcaller's Path" quest.
Complete "The Taken King" quest.
Complete "The Nightstalker's Trail" quest.
Complete "The Old Hunger" quest.
Complete the "Echoes of Oryx" quest.
Complete the King's Fall Raid.
Complete the King's Fall Raid (Heroic).