Here is the full list of all 50 Battlefield: Bad Company achievements worth 1,000 gamerscore.
Got 10002 kills
Achieved all the awards
20 Squad members spawned on you and you didn't die!
Achieved half of all awards
Reached Rank 25
100 kills using vehicle
Knocked down 1000 trees
Reached Rank 20
Completed 'Ghost Town' on normal
Found all gold bars
Completed 'Crash and Grab' on normal
Got at least one kill in every vehicle
Completed 'Air Force One' on normal
Completed 'Par for the Course' on normal
Completed 'Crossing Over' on normal
Completed one mission without dying (any difficulty)
Completed 'Acta Non Verba' on normal
Completed 'Welcome To Bad Company' on normal
Played 100 online matches
There is no parachute, right?
Destroyed 1000 walls
Collected 50 unique dog tags
Used Squad in the menu, found a friend and played one round
Placed #1 in a Ranked Match
Collected 5 unique dog tags
Took 3 pictures using the image system
Reached Rank 8
Reached Rank 3
Completed 'Ghost Town' on hard
Found all collectables
Found half of the gold bars
Completed 'Crash and Grab' on hard
Hit hostile helicopter with laser designator
Climbed to the highest spot in the game
Completed 'Air Force One' on hard
Killed 25 enemies in a helicopter
Knocked down a small forest
Destroyed 50 vehicles. (containing enemy AI)
Drove all vehicle types (Jeep, Tank, Heli, Boat)
Completed 'Par for the Course' on hard
Found half of all collectables
Completed 'Crossing Over' on hard
Completed 'Acta Non Verba' on hard
Destroyed 200 Walls
Found 5 unique collectables
Found one gold bar
Played one complete ranked online match
Completed 'Welcome To Bad Company' on hard
Used auto Injector 50 Times
Killed 25 enemies