Here is the full list of all 51 Spec Ops: The Line trophies - there are 42 bronze, 5 silver, 3 gold and 1 platinum.
Kill 250 enemies with headshots. (campaign only)
Live and let die.
Complete game on "Combat Op" difficulty.
Complete game on "Walk on the Beach" difficulty.
Carry on, soldier.
The end of the line.
Kill 50 enemies using only the Attack Command. (campaign only)
Choose vengeance.
Kill 350 enemies with any rifle. (campaign only)
Get out of here!
Kill 50 enemies with grenades. (campaign only)
Stand united.
Kill 5 enemies using blind fire. (campaign only)
Kick an enemy by vaulting over a cover. (campaign only)
Save a bullet.
Sprint into cover 10 times while under fire. (campaign only)
Stun an enemy by dumping sand on their head. (campaign only)
Follow your orders.
Play it loose.
Kill an enemy by tagging him with a sticky grenade. (campaign only)
Kill 100 enemies with any pistol or SMG. (campaign only)
Kill an enemy just as they are throwing a grenade. (campaign only)
Face the horrors of war.
Hit 10 enemies with your melee attack. (campaign only)
Kill an Edged Weapon Expert while he is up to 5 meters away. (campaign only)
Engineer an exit strategy.
We have contact.
Look out below.
Kill 3 enemies with a single grenade. (campaign only)
Recover one Intel Item.
What's lost is found.
Unlock all Trophies.
Play it smart.
Buck the chain of command.
Show mercy.
Choose restraint.
You are relieved.
Live and let live.
Complete game on "Suicide Mission" difficulty.
Complete game on "FUBAR" difficulty.
Kill 75 enemies with any shotgun. (campaign only)
Kill 50 enemies with any sniper rifle. (campaign only)
Kill 150 enemies with any heavy weapon. (campaign only)
Blow up 10 explosive objects, killing at least one enemy each time. (campaign only)
Kill 4 enemies with a shotgun in 10 seconds or less. (campaign only)
Kill 10 enemies while they use zip lines or are rappelling. (campaign only)
Complete three chapters in a row without being killed or reloading a checkpoint.
Complete any chapter with 60%+ accuracy without dying or reloading a checkpoint.
Kill an oryx. (campaign only)
Recover 12 Intel Items.
Recover all Intel Items.