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