Here is the full list of all 50 The Witcher 2: Assassins of Kings (EU) achievements worth 1,000 gamerscore.
Survive your 5th fight in the Arena
Finish the game by killing Letho.
Kill the dragon.
Finish the game at any difficulty level.
Finish the game by sparing Letho.
Complete Chapter 3.
Spare or save Saskia.
Leave Síle to die in the unstable portal.
Finish all quests involing the destruction of monster nests.
Complete Chapter 2.
Spare all trolls in the game.
Kill a foe by deflecting his own arrow at him.
Kill the draug.
Relive all of Auckes's memories in Dethmold's vision.
Kill 500 foes.
Kill more than one opponent using a single exploding bomb.
Seduce Ves.
Defeat all opponents in the Kaedweni arena.
Complete Chapter 1.
Craft a suit of armor from elements of the kayran's carapace.
Achieve character level 10.
Kill the kayran.
Find all additional information about the insane asylum's history.
Perform three successful ripostes in a row.
Hire a craftsman to create an item.
Win an arm wrestling match, a dice poker game and a fist fight.
Intimidate someone.
Use alchemy to brew five potions or oils.
Complete the Prologue.
Kill 10 foes in a row without losing any Vitality.
Hit Count Etcheverry using the ballista.
Acquire the Mutant ability.
Collect 10000 orens.
Finish the game while playing at the Dark difficulty level.
Help Roche rescue Anais from the Kaedweni camp.
Achieve character level 35.
Acquire the Sense of Magic ability.
Enhance abilities using mutagens at least five times.
Survive your 30th fight in the Arena
Roll five-of-a-kind at dice poker.
Save Síle from dying in the unstable portal.
Successfully sneak through Loredo's garden and find the component of the kayran trap.
Sneak through the lower camp without raising the alarm.
Help Iorveth find the dagger needed to free Saskia from the spell that holds her.
Stop Roche from killing Henselt.
Acquire the Combat Acumen ability.
Cut off a tentacle using the kayran trap.
Tour the camp with Zyvik.
Kill three foes at once by performing a group finisher.
Kill all the trolls in the game.