Here is the full list of all 50 Battlefield: Bad Company achievements worth 1,000 gamerscore.
Played 100 online matches
Knocked down 1000 trees
Destroyed 1000 walls
Destroyed 200 Walls
Found 5 unique collectables
Used auto Injector 50 Times
Found one gold bar
There is no parachute, right?
Collected 5 unique dog tags
Reached Rank 8
Took 3 pictures using the image system
Reached Rank 3
Used Squad in the menu, found a friend and played one round
Completed 'Welcome To Bad Company' on normal
Killed 25 enemies
Played one complete ranked online match
Complete 'Welcome To Bad Company' on hard
Complete 'Acta Non Verba' on normal
Complete 'Acta Non Verba' on hard
Complete 'Crossing Over' on normal
Complete 'Crossing Over' on hard
Complete 'Par for the Course' on normal
Complete 'Par for the Course' on hard
Complete 'Air Force One' on normal
Complete 'Air Force One' on hard
Complete 'Crash and Grab' on normal
Complete 'Crash and Grab' on hard
Find half of all collectables
Complete one mission without dying (any difficulty)
Complete 'Ghost Town' on normal
Complete 'Ghost Town' on hard
Kill 25 enemies in a helicopter
Knock down a small forest
Destroy 50 vehicles. (containing enemy AI)
Drive all vehicle types (Jeep, Tank, Heli, Boat)
Hit hostile helicopter with laser designator
Find all collectables
Find half of the gold bars
Find all gold bars
Climb to the highest spot in the game
(Online) Have 20 Squad members spawn on you without dying in a single round
(Online) Collect 50 unique dog tags
(Online) Place #1 in a ranked match
(Online) Get at least one kill in every vehicle
(Online) Reach Rank 20
(Online) Reach Rank 25
(Online) 100 kills using vehicle
(Online) Achieve all the awards
(Online) Achieve half of all awards
(Online) Get 10002 kills