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