Here is the full list of all 50 South Park: The Stick of Truth achievements worth 1,000 gamerscore.
You have joined the KKK
You completed your first day in South Park
You defeated the High Jew Elf Kyle in battle
You defeated the Grand Wizard Cartman in battle
You befriended the Goths, like everyone else playing this game
Gingers have bitten you 3 times without you blocking
You defeated the Boss Hall Monitor while wearing freckles
You flung a turd of your own creation at an enemy
While inside Mr. Slave, you summoned Mr. Slave
You found Jesus while playing as a Jew
You opened all of the garages in South Park
You completed the game without selling any items
You defeated Princess Kenny while looking like David Hasselhoff
You farted on four major authority figures
You shat your pants during a boss battle
You accepted your fate and chose the name Douchebag yourself
You've farted on a dog while in gnome form
You knocked out 3 or more enemies with a single fart outside of battle
You defeated Princess Kenny in your girl makeover disguise
You've farted on every buddy in the game
You interrupted 5 channel attacks by using a fart
You defeated the Meth Tweekers while wearing the Evil Cartman goatee and bald cap
You defeated Princess Kenny while living with Dire AIDS
You watched your parents have sex for 60 seconds
You successfully blocked every enemy attack in a single (non-tutorial) battle
You farted on 10 enemies in the world that were knocked out
You defeated 3 enemies in one battle while your buddy was knocked out.
You completed the game and never ended a battle with your buddy knocked out
You collected 5 Chinpokomon
You collected 15 Chinpokomon
You collected all of the Chinpokomon
You befriended your father
You made friends with half of South Park
Everyone in South Park is your friend
You sold 300 junk items
You defeated Princess Kenny and recovered the Stick of Truth
You defeated 20 enemies using Cartman's Ass
You've farted on people 100 times.
You've farted on animals 25 times
In three separate battles, you've taken a shit in your pants
You have collected half of the available costume sets
You've collected all of the available costumes
You farted on the corpse of an aborted Nazi Zombie fetus
You befriended both crab people and gnomes
Over the course of the game, you've scored 100 perfect attacks
Over the course of the game, you've blocked 100 attacks
You've let Kenny die in combat 10 times over the course of the game
You've unlocked all of the upgrades for a New Kid ability
You've spent $500
You own all the weapons and costumes available in the game