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