Here is the full list of all 57 Star Wars Knights of the Old Republic II: The Sith Lords achievements.
Reduce a companion's Influence to zero.
Recruit the Disciple
Learn how to kill Jedi from HK-47
Acquire all Dark Side Powers.
Deduce G0-T0's identity
Teach the Handmaiden the ways of the Force.
Complete the game on the Light Side
Reach Player Level 30
Acquire all Light Side Powers
Install HK-47's unique module
Side with the Queen on Onderon
Have 30 points in Stealth
Have 30 points in Treat Injury.
Have 30 points in Demolitions.
Listen to HK-47's definition of love.
Win a Pazaak game with a full board
Learn Force Sight
Recruit the Handmaiden
Complete the Handmaiden Battle Circle
Complete the game on the Dark Side
Defeat Sion
Claim Darth Nihilus' mask.
Defeat Nihilus
Have your character replace any of the Sith Lords on the main menu screen.
Break Hanharr's spirit
Kill all the Jedi masters
Side with Vaklu on Onderon
Complete the Mandalorian Battle Circle
Convince Vogga the Hutt to sell fuel to Telos.
Recruit Hanharr
Have 30 points in Repair.
Have 30 points in Computer Use.
Beat the champ on Nar Shadaa
Convince the "champ" to lose the game without playing.
Flee Korriban after fighting Sion
Loot a body on Korriban
Get this by starting the "Trapped" Quest on Korriban.
Change your mind about siding with the Settlers at Khoonda
Gain a Prestige class
Contruct your first Lightsaber
Side with the Settlers at Khoonda
Reach maximum Dark Side points
Kill all Sith troopers before they can board the Ebon Hawk
Dance for Vogga
Get your first Dark Side points
Get the named Lightsaber crystal
Fill the Party Selection screen
Repair the damaged droid on the Ebon Hawk
Have Persuasion over 30
Recruit Mira
Learn Moving Meditation
Collect 10,000 credits
Reach maximum Light Side points
Destroy Peragus Astroids
Let the Sith destroy the Peragus Asteroids
Get your first Light Side points
Complete the Prologue