Started this thread to make crazy acheivements for games (that are actually possible!) to see what you all come up with, i'm even suggesting to try other peoples fictional acheivements to see who is a pro gamer
Gears of War (original)
It's Pronounced SNY e PAH - While in cover, blindfire someone's head off with the sniper as they blindfire from a different set of cover in a Ranked or Player match. (Done)
Maybe Next Time - Headshot someone with the Sniper while they are doing the weapon slide glitch in a Ranked or Player match. (Done)
Revolver Ocelot - Headshot four opponents in one round with the Snub Pistol in a ranked match. (my best is 3

)
Twofer - Get 2 kills with one shot of the Shotgun in a ranked match. (Done)
Call of Duty 4
Forrest Gump - Go an entire ranked match without sprinting, crouching, or going prone but still finish 1st in the match overall.
With My Eyes Closed - Get a Blindfire headshot in any ranked match directly after getting hit with a flash grenade. (Done. Yeah i was amazed too

)
Miyamoto Musashi - Get 60 kills without dying in any ranked match. (personal best is 43-2

)
The A Team - 4 Members of your team place in the top 4 overall in a Team Hardcore Match.
pWn TeH n00b - Get a headshot from 50 feet away while shooting a sniper rifle from the hip. (done. It was histericle)
Left 4 Dead
Born Ready - Complete a Campaign with none of your teammates picking up Med Kits, Pain pills, or Weapons of ANY kind.
Did You Hear Something? - Complete a Campaign on expert with Music and FX volumes all the way down.
Careful... - On Versus Mode, live through an entire chapter in one life as a Boomer.
Why me? - Simultaneously get vomited on by a Boomer and pounced on by a Hunter, and live to tell the tale.
Gears of War 2
Dirty Harry - Headshot all 5 opponents with the Boltok Pistol in a Ranked match.
Kickin' It Old School - Complete a Ranked Match with NOBODY melee-ing each other (Improbable in Gears 2 which is why i

hate it now)
My Other Half - Complete Horde Mode on Hardcore with only 1 other teammate. (done)
Bioshock (Credit to PoeticMadnesss from the 2K Forums.) <---I choose my favorite ones i think they are a riot.
Let Dead Men Lie - Beat the game without searching any corpses
Blind and Deaf - Beat the game with the brightness turned all the way down and the sound off
Numb Fingers - Beat the game with controller sensitivity at 0
Over-Stimulating - Beat the game with controller sensitivity at 100
Drug Hoarder - Beat the game without spending any ADAM
I Choose the Benevolent - Beat the game without directly killing Big Daddies or splicers. Turrets, bots, cameras, enrage, and static discharge are INDIRECT methods. (First applies in Neptune's Bounty)
Big Daddy Savior - Beat the game with killing no Big Daddies other than the one in Point Prometheus and the ones necessary to get the R-34 cables.
More of PoeticMadnesss's list can be found
here
[PROTOTYPE]
Only The Prime Rib - Complete story mode without consuming any infected Humans (Hunters are allowed)
Chuck Norris Must Be Your Father - Complete story mode without using any attack transformations. (Applies after the introduction mission)
Where's Tim? - Kill every enemy inside a Military base without raising alarm. (Done, weirdly enough you dont get a bonus after you kill the last one. :()
Dawn of War 2
Massacre - Complete the first 10 missions of story mode without failing on Primarch difficulty.
Product Loyalty - Complete the campaign on primarch difficulty without changing equipment and only using the first four available squads-Commander, Avitus, Tarkus and the scout squad.
More Dakka - Play 500 online games in a row as Orks.
Fallen to the Xenos- Lose 100 matches as the space marines against eldar online.
Resident Evil 5
Who Needs Ammo? - Kill an Executioner using only the knife.
Be by my Sidearm - Kill 3 Lickers in a row using only the M92F.
Steve Irwin Reborn - Narrowly dodge getting eaten by a Crocodile 3 times in 5 seconds.
Tekken: Dark Resurrection
Untouchable - Achieve 'Tekken Lord' status with a rank consisting of 0 losses.
Is this game hacked? - Achieve 'Tekken Lord' status with all characters.
Fashion Junkie - Collect every piece and color of clothing in customize mode.
Soul Calibur IV
Quit cheating! - In an online match, hit your opponent once, and then guard impact 10 of their moves in a row without taking any damage.
I am your father - Win 50 consecutive online matches as a Star Wars character.
Overtime - Get three Draws in a row.
Grand Theft Auto IV
Strike! - Knock ten people over by flying out of your windshield.
I Saw This In a Game - Blow up 10 cars in a row while driving an ice cream truck.
Sex addict - spend 5000$ all together on hookers (done)
Saint - kill people that are only required to kill in missions
Going Cold Turkey - Don't commit any crimes for 7 straight in game days. (includes, assualt, hit and run, murder, theft, evading arrest, or attempted murder)
Andre Arlovski - Win a fist fight against 4 simultanious opponents.
Team Fortress 2
Knock it off Dick! - Heal a friendly spy disguised as an enemy until he dies.
Unluckiest Spy Ever - get shot in the head while cloaked, without the sniper even knowing a spy is nearby.
Is Everyone Else Asleep? - Win a payload match, without any help from your team, by crouching behind the kart and hoping nobody shoots you.
I Know All His Moves... - As a Demo, kill an enemy Demo and then die from his pipe bomb.
It's a Dud! - Kill someone by hitting them directly with a grenade (before it explodes).
Fable II
Promiscuous - Have three wives or husbands in the same city, without any of them leaving you.
Fallout 3
Bookworm - Get 100 points in every skill. (For those of you who don't know, you pretty much have to collect every single skill book in the game to be able to do that.)
Last Ditch Effort - Get 5 Kills with under 20 Health.
Chem Dependant - Use 500 Stimpacks.
Arsenal - Collect every unique weapon in the game (Excluding either the Ant's Sting or Protectron's Gaze)
Kamikaze - UsKill a Super Mutant Behemoth without using any long-range weapons.
Inhuman - Accrue 999 rads and live for at least five minutes.
The Elder Scrolls IV: Oblivion
Demigod - Achieve level 200.
Scholar - Read every book in the game.
Inmate - Achieve level 200.
Affluent - Gain 100,000,000 Septims.
Final Fantasy Tactics: The War of the Loins
Addiction - Achieve level 99 with at least five characters.
Unhealthy Addiction - Master all jobs with at least five characters.
Life is for the Weak - Achieve maximum stats for at least five characters.
Masochist - Beat the majority of the story battles using only Onion Knights.
Zodiac Brave - Beat the game using only Ramza.
You Should Have Seen This Coming - Kill Luso while he is in your party, and use his crystal for
JP.
Time Paradox - Achieve level 99 with both Balthier and Cloud.
An Ignominious End - Kill Ultima with the skill 'Throw Stone'.
Saints row 2
Bust A Cap In Yo Ass - Shot pedestrians in the ass 40 times
The Last Samurai - play through the entire ronin last leval using just the sword.
PIMPIN YO RIDE - customize every customizable vehicle.
Animal Crossing
WHY DO I LOVE IT SO MUCH?! - Play Animal Crossing for 500+ hours.
Geometry Wars: Retro Evolved 2
Epileptic Chaos - Complete Sequence mode without losing any lives, timing out, or using any of your trigger bombs.
Original Gamer - Get 10,000,000 points in any mode while having your gun and movement set to the same analog stick.
i'll upload more when i think of them, Post if you've done these or would like to come up with any fictional extreme acheivements post them and Challenge each other!
DOES NOT have to be on the Xbox 360, you can create acheivements for any game on any system, the only rules i have are this -
1. MUST come up with a name for it! (its part of the fun)
2. MUST be actually possible to do! Improbable is fine it just has to be a POSSIBLE to complete.