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