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