Here is the full list of all 78 The Witcher 3: Wild Hunt - there are Complete Edition achievements worth 2,000 gamerscore.
Find Yennefer of Vengerberg.
Kill 5 foes in a fight without taking damage (except for Toxicity) and without using the Quen Sign.
Have all possible Place of Power bonuses active at the same time.
Find the baron's wife and daughter.
Perform 10 effective counterattacks in a row without getting hit or parrying.
Learn 12 potion formulae.
Complete the contract on the shrieker.
Kill 2 monsters you have a contract on without using Signs, potions, mutagens, oils or bombs.
Kill at least 5 opponents in under 10 seconds.
Read 30 books, journals or other documents.
Defeat an opponent in a fistfight without taking any damage.
Attack, counter, cast a Sign and throw a bomb (in any order) in under 4 seconds.
Find and free Dandelion.
Obtain a flawless victory in all the competitions during the knights' tourney.
Play three hero cards in one round of gwent and win the match.
Find and equip all the elements of one set of witcher gear.
Complete the contract on Therazane.
Collect the formulae for 6 different bomb types.
Complete all fistfighting quests in Velen, Skellige and Novigrad.
Defeat Olaf, the Skellige champion of unarmed combat.
Be under the influence of seven potions or decoctions at the same time.
Acquire all gwent cards available in the base version of the game.
Recreate all of Iris' nightmares in the Painted World.
Kill Golyat with a crossbow bolt to his eye.
Acquire all the Abilities in one tree.
Unlock the bonus for equipping all the witcher gear elements from one School.
Be given Aerondight by the Lady of the Lake.
Kill 50 opponents using the environment (e.g. swamp gas, insects or objects).
Win all the horse races in the game.
Complete the contract on Sarasti.
Complete the contract on Morvudd.
Destroy 10 monster nests using bombs.
Complete the subplot involving Keira Metz.
Bring all possible allies to Kaer Morhen for the battle against the Hunt.
Win a round of gwent using only neutral cards.
Complete all witcher contracts.
Discover 100 fast travel points.
Defeat Tybalt and win the gwent tournament held at the Passiflora.
Kill a frozen opponent with a crossbow bolt.
Kill 10 opponents by knocking them off somewhere high with the Aard Sign.
Collect all the cards in the Skellige deck.
Collect all available Ofieri armor and horse gear, and at least one Ofieri sword.
Kill the prince cursed into a toad.
Win a round of gwent with a total strength of at least 187.
Complete the subplot about choosing Skellige's ruler.
Serve time in Toussaint.
Be decorated with the Order of Vitis Vinifera.
Participate in all the activities at the wedding.
Kill 50 human and nonhuman opponents by striking them in the head with a crossbow bolt.
Kill 20 cows.
Reach character development level 35.
Fill all mutagen slots.
Help Yennefer extract information from Skjall's body.
Make an opponent suffer from bleeding, poisoning and burning simultaneously. Do this 10 times.
Finish the "Hearts of Stone" expansion.
Finish the game on any difficulty.
Destroy all monster nests in the Velen / Novigrad region, or in Skellige.
Use all available options for developing Corvo Bianco.
Slide downhill uninterrupted for at least 10 seconds.
Finish the game on the "Blood and Broken Bones!" or "Death March!" difficulty levels.
Kill 3 opponents with their own arrows.
Buy all the items put on the block at the Borsodis' Auction House.
Find Ciri.
Ignite the gas produced by a Dragon's Dream bomb using a burning opponent. Do this 10 times.
Resolve the doppler problem in Novigrad.
Use the Axii Sign to force one opponent to kill another. Do this 20 times.
Help unite the warring vineyards and have a wine named in your honor.
Defeat Eredin.
Travel to the Duchy of Toussaint.
Kill 3 opponents in one fight using 3 different methods (swords, bombs, crossbow, Signs, etc.).
Find all grandmaster diagrams for each witcher school.
Finish the game on the "Death March!" difficulty level.
Develop a mutation.
Provoke all Iris von Everec's Nightmares into fighting you at the same time and defeat them.
Defeat all the fallen knights and loot their campsites.
Complete the contract on the Woodland Spirit.
Visit Tir ná Lia and convince Ge'els to betray Eredin.
Take part in the assassination of King Radovid.