Normally, going for all achievements in a 360 game earns Mavrixx mocking. Gamerscores are for epeens. However, the folks at bioware made the achievements in mass effect actually MEAN something.
This is taken from a NEOGAF post.
AI Hacking Specialist --- Unlocks Talent 'Reverse Engineering' for future characters.
Assault Rifle Expert --- Unlocks Talent 'Assault Rifle' for future characters.
Barrier Mastery --- Unlocks Talent 'Barrier' for future characters.
Charismatic --- No Benefit other than Gamerscore
Completionist --- +5% Experience Reward Bonus
Council Legion of Merit --- No Benefit other than Gamerscore
Damping Specialist --- Unlocks Talent 'Shielding' for future characters.
Distinguished Combat Medal --- Unlocks Insanity Difficulty and Gamer Picture(Final Boss)
Distinguished Service Medal --- No Benefit other than Gamerscore
Dog of War --- +10% Health Bonus
Extreme Power Gamer --- Another XP bonus (Reach Level 60)
First Aid Specialist --- First-aid/Fitness for all (150 Medi-Gel Uses)
Geth Hunter --- +10% Shield Strength Bonus
Honorarium of Corporate Service --- No Benefit other than Gamerscore
Lift Mastery --- Unlocks Talent 'Lift' for future characters.
Long Service Medal --- 5% Weapon Damage Bonus
Medal of Exploration --- No Benefit other than Gamerscore
Medal of Heroism --- No Benefit other than Gamerscore
Medal of Honor --- Unlock Hardcore Difficulty, Unlock Levels 51-60
Medal of Valor --- Gamertag pic (Beat Insanity)
Neural Shock Specialist --- Unlocks Talent 'Medicine' for future characters.
Overlord Specialist --- Unlocks Talent 'Electronics' for future characters.
Paragon --- No Benefit other than Gamerscore
Paramour --- No Benefit other than Gamerscore (And Sweet Lovin')
Pistol Expert --- Marksman Duration +25%
Power Gamer --- +10% Experience Reward Bonus (When combined with RIch, allows purchase of Spectre Weapons at grade X)
Renegade --- No Benefit other than Gamerscore
Rich --- Spectre Weapons available for Purchase
Sabotage Specialist --- Unlocks Talent 'Decryption' for future characters.
Search and Rescue --- No Benefit other than Gamerscore
Shotgun Expert --- Unlocks Talent 'Shotgun' for future characters.
Singularity Mastery --- Unlocks Talent 'Singularity' for future characters.
Sniper Expert --- Unlocks Talent 'Sniper Rifle' for future characters.
Spectre Inductee --- No Benefit other than Gamerscore.
Stasis Mastery --- Unlocks Talent 'Stasis' for future characters.
Tactician --- +10% Shield Strength
Throw Mastery --- Unlocks Talent 'Throw' for future characters.
Warp Mastery --- Unlocks Talent 'Warp' for future characters.
Very...very cool.
