Here are some acheivements that can get you 5 - 15 Xbox Live Gamerscore Points:

Basic Training (5) - Complete the basic training in the beginning of Saint Lo.5.
Purple Heart (5) - For perserverence despite grevious injuries.
Canadien Highlander (10) - Complete 2 missions as a Canadien Soilder.
Polish Tanker (15) - Complete 2 missions as a Polish Soilder
Battle Scavenger (15) - Complete a mission by firing only German weapons. Melee attacks DO NOT count.
Assault Trooper (15) - Complete a mission by firing only assault rifles. Melee attacks DO NOT count.
Supply Officer (15) - Supply ammunition to at least 20 friendly soldiers in a single ranked match. (Multiplayer only)
Rifleman (15) - Complete a mission by firing only bolt action rifles. Melee attacks DO NOT count.