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