Splinter Cell: Double Agent Cheats - Xbox 360

Achievements
Complete each of the following achievements below to get the allotted gamerscore:

Agent of the Month (20) - Complete the profiles of all the major members of the JBA.
BLACKWING Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
BOSS HOUSE Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
Bronze Trophy (15) - Complete all the challenges by obtaining at least the bronze medal.
COMMANDER (45) - Obtain an overall characteristics average of over 95%.
DAWN WAVES Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
Ellsworth Assignment Completed (30) - In solo mode, completed the Ellsworth Penitentiary assignment.
FIELD AGENT (20) - Obtain an overall characteristics average of over 20%.
Getting Technical (20) - In solo mode, knock out 5 enemies using non-lethal gadgets.
Gold Trophy (50) - Complete all the challenges by obtaining at least the gold medal.
Hero (20) - In solo mode, complete the game with the best ending.
Iceland Assignment Completed (30) - In solo mode, completed the Iceland assignment.
MOTORWAY 90 Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
OFFICER (30) - Obtain an overall characteristics average of over 75%.
OPERATIVE (15) - Obtain an overall characteristics average of over 5%.
Professional Ninja (40) - Complete solo mode on Hard difficulty.
RECRUIT (10) - Obtain an overall characteristics average of over 1%.
RED DIAMOND Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
Silver Trophy (30) - Complete all the challenges by obtaining at least the silver medal.
SLAUGHTER HOUSE Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
SPECIAL AGENT (25) - Obtain an overall characteristics average of over 45%.
Teacher's Pet (40) - In solo mode, successfully complete all of the training courses.
TERMINUS Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.
The Collector (20) - In solo mode, collect all gadgets and upgrades.
The Human Light Switch (20) - In solo mode, use your EMP Pistol to turn off 20 light sources.
The Invisible Man (20) - In solo mode, complete a mission without being detected.
Training Completed (10) - In solo mode, successfully complete a training course.
USS WISDOM Expert (20) - Get at least 10 victories as a spy and 10 in the UPSILON FORCE and play 25 sessions in this map.

Get more skins for your character
You have to play multiplayer to get those skins:

Spy (second skin) - Achieve RECUIT level with a general average higher that 1%
Spy (third skin) - Achieve SPECIAL AGENT level with a general average higher than 45%
Uspilon Forces (second skin) - Achieve FIELD AGENT level with a general average higher than 20%
Uspilon Forces (third skin) - Achieve COMMANDER level with a general average higher than 95%

Unlock all multiplayer maps
Win 6 games as a Spy, 6 games as a UPSILON Force member, and play 25 games overall.

Unlockable Equipment
Complete the special objectives in single player to unlock them for single player play. You can tell what objectives by the star next to them.

Electric Lock Pick - Complete the primary objectives in JBA HQ 1
EMP Device (Enhanced) - Complete the primary objectives in JBA HQ 1
EMP Grenade - Complete the secondary objectives in the Iceland Assignment
EMP Grenade (Attachment) - Complete the secondary objectives in the Cozumel Assignment
Explosive Sticky Camera-Attachment - Complete the secondary objectives in the Iceland Assignment
Frag Grenade (Attachment) - Complete the primary objectives in JBA HQ 3
Gas Grenade - Complete the primary objectives in JBA HQ 1
Gas Grenade (Attachment) - Complete the secondary objectives in the Cozumel Assignment
Hacking Device - Force Hack Upgrade - Complete the primary objectives in JBA HQ 2
Hacking Device - Software Upgrade - Complete the secondary objectives in the Shanghai Assignment
Night Vision (Enhanced) - Complete the primary objectives in JBA HQ 3
Shotgun Shell (Attachment) - Complete the secondary objectives in the Okhotsk Assignment
Smoke Grenade (Attachment) - Complete the secondary objectives in the Shanghai Assignment
Sonic Grenade (Attachment) - Complete the primary objectives in JBA HQ 2
Ultrasonic emitter - Complete the secondary objectives in the Ellsworth Assignment
Wall Mine (Flash) - Complete the secondary objectives in the Okhotsk Assignment
Wall Mine-stun - Complete the secondary objectives in the Ellsworth Assignment

Unlock Three Different Endings
In the last mission, When the bomb is disarmed, a number of different endings can play out. To unlock each ending take the fallowing steps below. Note: The targets listed below are the Cruise Ship, Hisham, and Lambert.

Ending A (Good) - NSA trust above 33%, and you managed to save at least two of the three targets.
Ending B (Normal) - NSA trust below 33%, but you managed to save the three targets. Or destroy two of the three targets, and NSA trust above 33%.
Ending C (Bad) - Destroy/Kill all three targets. Or Destroy/Kill two of the targets, and NSA trust below 33%.