Here is the full list of all 50 Middle-earth: Shadow of Mordor achievements worth 1,000 gamerscore.
Brand 5 Bodyguards of a Warchief, turning them against him in combat.
Liberate 20 slaves in 300 seconds while riding a caragor.
After an uruk kills you to become a Captain, help him become a Warchief, then kill him.
Capitalize on a Warchief's Fear.
Help a Captain survive a Recruitment Power Struggle, and then kill him and all his new recruits.
Complete all Hunting Challenges.
Complete all Survivalist Challenges.
Complete all Outcast Rescue Missions.
Collect 100% of the Artifacts and listen to their memories.
Successfully complete 4 Hunting Challenges.
Perform an Execution on a flaming Berserker.
Kill The Black Hand.
Kill The Tower.
Brand all 5 Warchiefs.
Complete all Urfael Legend Missions.
Issue a Death Threat, and then successfully kill the target.
Use Strike From Above while at least 60 feet above your target.
Collect 100% of the Ithildin.
Complete all Azkâr Legend Missions.
Poison a Captain at his own Feast.
Save Lithariel's life.
Start a Riot by commanding a Warchief to attack another Warchief.
Complete all Acharn Legend Missions.
Lift Lady Marwen's curse.
Brand a Captain while in combat.
Kill the Great White Graug.
Activate all Forge Towers.
Collect 50% of the Ithildin.
Make 20 uruks flee by dropping Morgai Fly nests.
Kill all 5 Warchiefs before any uruk take their place.
Kill The Hammer.
Destroy the Monument Gate and topple the statue of Sauron.
Attract caragors with bait 5 times.
Collect 25% of the Artifacts.
Unlock 4 Dagger Rune slots.
Complete a Bow Mission and begin growing the legend of Azkâr.
Unlock 2 Bow Rune slots.
Complete a Dagger Mission and begin growing the legend of Acharn.
Make an uruk yours.
Discover some of the Wraith's past.
Free 5 caragors from cages.
Successfully complete a Survivalist Challenge.
Use the Detonate ability to burn 50 uruks.
Eliminate the bodyguards of two Warchiefs, then draw them out and kill them.
Witness the creation of The Rings of Power.
Complete an Outcast Rescue Mission.
Get Ratbag promoted to Warchief.
Complete a Sword Mission and begin growing the legend of Urfael.
Unlock 3 Sword Rune slots.
Acquire a level 25 Rune.