Full list of all 65 Left 4 Dead achievements worth 1,500 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 15 achievements worth 500 Gamerscore.
Kill 53,595 Infected.
Survive all campaigns on Expert.
Kill a Witch with a single headshot.
Survive any campaign on Expert.
Revive 50 incapacitated Survivors.
Headshot a Hunter while he's leaping.
Survive the Dead Air campaign.
Kill 1000 Infected with a mounted machine gun.
Survive the No Mercy campaign.
Kill 10 Smokers as they are pulling helpless Survivors.
No Survivors take damage after contacting the rescue vehicle.
Play an entire campaign with no Survivors taking friendly fire damage.
Dole out 5000 total Survivor damage as a Special Infected.
Leave a safe room to save an incapped teammate and bring them back safely.
Survive the Death Toll campaign.
Finish a campaign without ever being healed.
Shove a Hunter off of a pinned and helpless Survivor.
Save another Survivor from a Special Infected while on the ground.
Survive the Blood Harvest campaign.
Survive a campaign with no Survivors taking damage from Special Infected.
Heal 25 Survivors with a first aid kit.
Kill all four Survivors in one life while playing as a Tank.
Light a Witch with a Molotov.
Heal a fellow Survivor when your own health is below 10.
Single-handedly kill a Tank.
Rescue a Survivor trapped in a closet.
Kill a Witch without any Survivor taking damage from her.
You or another Survivor take no damage after being vomited on by a Boomer.
Protect any Survivor from an attacking Infected 50 times.
Give pain pills to 10 Survivors.
Pounce two different Survivors in one life as a Hunter.
Constrict two Survivors in one life as a Smoker.
Shove a Boomer and then kill him without him splashing on anyone.
Drag a Survivor 100 feet with your tongue.
As an Infected, incap a Survivor who has entered and left a safe room.
Cover four Survivors with Boomer bile at once.
Light a Tank with a Molotov.
Set 101 Infected on fire.
Punch a Hunter as he is pouncing.
Free yourself from a Smoker who has grabbed you with his tongue.
Kill a Tank without it dealing any damage to a Survivor.
Make 100 headshot kills.
All Survivors complete a campaign without being vomited on.
Survive a campaign without being incapacitated.
Sneak past all Witches in a campaign without disturbing one.
Survive an entire campaign using only pistols.
Beat a campaign with all 4 Survivors.
Blow up 20 Infected in a single explosion.
Rescue a Survivor from a Smoker's tongue before he takes damage.
Kill an Infected with a single blow from behind.
Smoker pull a bile-covered Survivor until you hold him during Crash Course.
Kill 5,359 Infected in the Crash Course campaign.
Pounce a Survivor for 25 points of damage in the Crash Course campaign.
Your team wipes all Survivors after the escape vehicle has opened in Crash Course.
Stun a Tank with an explosion in the Crash Course campaign.
Survive the Crash Course Campaign.
Win a Versus campaign of Crash Course.
Restart the generator within 30 seconds of it shutting off in the Crash Course campaign.
Your team incapacitates three Survivors within five seconds in the Crash Course campaign.
As a Tank hit 20 Survivors with a car in the Crash Course campaign.
Have all 3 generators running at once in "The Sacrifice" finale.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".