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