This page lists the Achievements by Game that you may add to your Achievement Trading Profile.
If you're chasing an acheivement that's not listed you can request it's added to the database.

If no game is selected the Top 5 Most Wanted Achievements are displayed.
Filter by Game:

Seriously ... - 50
Kill 10,000 people in versus ranked match total
[121 whores] - [add to my profile] - [0 sessions] - [create session]

Two for One - 5
Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online).
[99 whores] - [add to my profile] - [0 sessions] - [create session]

Overkill - 5
Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
[95 whores] - [add to my profile] - [0 sessions] - [create session]

Maybe Next Time Buddy - 5
Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).
[81 whores] - [add to my profile] - [0 sessions] - [create session]

1,000,000 Online Credits - 30
Earn 1,000,000 "Online Credits" from Tournaments and Career races.
[79 whores] - [add to my profile] - [0 sessions] - [create session]

Achievements recently added to GSW database:
'Party Bus' from Crackdown 2 worth 10 gamerscore 'Squad City Glider' from Crackdown 2 worth 20 gamerscore 'Co-op Keepy-Up' from Crackdown 2 worth 10 gamerscore 'LIVE and let LIVE' from Crackdown 2 worth 10 gamerscore 'Star 69' from Modern Warfare® 2 worth 90 gamerscore 'A Friend Indeed' from Perfect Dark worth 10 gamerscore 'I am Bad Company!' from BF: Bad Company worth 25 gamerscore 'The Duellist' from Fable II worth 10 gamerscore