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