Left 4 Dead - Achievements

Helping Hand 20 points: Revive 50 incapacitated Survivors.
Field Medic 20 points: Heal 25 Survivors with a first aid kit.
Pharm-assist 20 points: Give pain pills to 10 Survivors.
My Bodyguard 15 points: Protect any Survivor from an attacking Infected 50 times.
Dead Stop 10 points: Punch a Hunter as he is pouncing.
Cr0wnd 30 points: Kill a Witch with a single headshot.
Untouchables 30 points: No Survivors take damage after contacting the rescue vehicle.
Drag and Drop 20 points: Rescue a Survivor from a Smoker's tongue before he takes damage.
Blind Luck 20 points: You or another Survivor take no damage after being vomited on by a Boomer.
Akimbo Assassin 30 points: Survive an entire campaign using only pistols.
Hero Closet 10 points: Rescue a Survivor trapped in a closet.
Hunter Punter 10 points: Shove a Hunter off of a pinned and helpless Survivor.
Tongue Twister 20 points: Free yourself from a Smoker who has grabbed you with his tongue.
No Smoking Section 15 points: Kill 10 Smokers as they are pulling helpless Survivors.
101 Cremations 20 points: Set 101 Infected on fire.
Do Not Disturb 20 points: Sneak past all Witches in a campaign without disturbing one.
Man vs Tank 30 points: Single-handedly kill a Tank.
Tankbusters 20 points: Kill a Tank without it dealing any damage to a Survivor.
Safety First 30 points: Play an entire campaign with no Survivors taking friendly fire damage.
No-one Left Behind 20 points: Beat a campaign with all 4 Survivors.
Unbreakable 30 points: Finish a campaign without ever being healed.
Witch Hunter 20 points: Kill a Witch without any Survivor taking damage from her.
Red Mist 20 points: Kill 1000 Infected with a mounted machine gun.
Pyrotechnician 20 points: Blow up 20 Infected in a single explosion.
Zombie Genocidest 20 points: Kill 53,595 Infected.
Dead Giveaway 10 points: Heal a fellow Survivor when your own health is below 10.
Stand Tall 20 points: Survive a campaign without being incapacitated.
Zombicidal Maniac 30 points: Survive any campaign on Expert.
What Are You Trying to Prove? 35 points: Survive all campaigns on Expert.
Nothing Special 30 points: Survive a campaign with no Survivors taking damage from Special Infected.
Burn the Witch 10 points: Light a Witch with a Molotov.
Towering Inferno 10 points: Light a Tank with a Molotov.
Spinal Tap 10 points: Kill an Infected with a single blow from behind.
Stomach Upset 20 points: All Survivors complete a campaign without being vomited on.
Brain Salad 15 points: Make 100 headshot kills.
Jump Shot 20 points: Headshot a Hunter while he's leaping.
Mercy Killer 15 points: Survive the No Mercy campaign.
Back 2 Help 20 points: Leave a safe room to save an incapped teammate and bring them back safely.
Toll Collector 15 points: Survive the Death Toll campaign.
Dead Baron 15 points: Survive the Dead Air campaign.
Grim Reaper 15 points: Survive the Blood Harvest campaign.
Ground Cover 30 points: Save another Survivor from a Special Infected while on the ground.
Clean Kill 10 points: Shove a Boomer and then kill him without him splashing on anyone.
Big Drag 20 points: Drag a Survivor 100 feet with your tongue.
Chain Smoker 20 points: Constrict two Survivors in one life as a Smoker.
Barf Bagged 20 points: Cover four Survivors with Boomer bile at once.
Double Jump 20 points: Pounce two different Survivors in one life as a Hunter.
All 4 Dead 30 points: Kill all four Survivors in one life while playing as a Tank.
Dead Wreckening 20 points: Dole out 5000 total Survivor damage as a Special Infected.
Lamb 2 Slaughter 20 points: As an Infected, incap a Survivor who has entered and left a safe room.