Here is the full list of all 50 Battlefield: Bad Company achievements worth 1,000 gamerscore.
Collected 50 unique dog tags
Got at least one kill in every vehicle
Reached Rank 8
20 Squad members spawned on you and you didn't die!
Knocked down 1000 trees
Destroyed 1000 walls
100 kills using vehicle
Placed #1 in a Ranked Match
Reached Rank 3
Collected 5 unique dog tags
Used Squad in the menu, found a friend and played one round
There is no parachute, right?
Took 3 pictures using the image system
Played one complete ranked online match
Killed 25 enemies
Complete 'Welcome To Bad Company' on normal
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 5 unique collectables
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
Destroy 200 walls
Use Auto Injector 50 Times
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 one gold bar
Find half of the gold bars
Find all gold bars
Climb to the highest spot in the game
(Online) Play 100 online matches
(Online) Reach Rank 20
(Online) Reach Rank 25
(Online) Achieve all the awards
(Online) Achieve half of all awards
(Online) Get 10002 kills