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