Create an Achievement/Trophie for any game.

[effilctar]

"Creedless: Kill 100 Civilians - 5G" Assassin's Creed

"Traitorous Douchebag: Team Up With The Other Group In Online Deathmatch - 5G" Halo 3

"Ammo Hungry: Kill Your Player Partners For Their Ammo 75 Times In One Mission - 5G" Halo 3

"Portal Suicide: Double Fling Into Radioactive Water - 5G" Portal

"Penis Deletion: Create a Penis Level That The Moderators Delete In Less Than 10 Minutes - 10G" Little Big Planet

These achievements encourage people to be a dick.

OT: Bioschock- Necromancer - kill a Big Daddy by hurling a body with telekenesis

 

[ryai458]

I think I'll go ahead and throw one of my ideas into the ring.

Halo 3 ODST- Untouchable- 20 GS Kill 100 opponents in firefight mode without dieing after the Catch, Tough Luck, and Black Eye skulls turn on.

thats easy peasy hunter squeezy

 

[GodofDisaster]

Cod4 throphies.

You must have cheated: Complete mile high on veteran, on your first try. (Gold trophy.)

GTFO of that corner *****: Kill 10 campers in a single online game. (Silver trophy.)

Do it again: Enter prestige mode for the first time. (Bronze trophy.)

I don't need no extra health: Kill three juggernut users, without using stopping power or sonic boom. (Bronze trophy.)

Edit: a new trophy for MW2.

I see your playing a different game now...er sort of: Play an hour of call of duty 4 then start a new game of Modern Warfare 2. (Yes I know it's not out yet)

 

[dalarz]

How the hell did you do that? - Beat castle crashers on hardcore by yourself with basic weapons and win without taking damage. -12.5 G

 

[ejb626]

"No John, you're the demons" I guess play on the side of the zombies in a Left 4 Dead VS match I just think it would be funny to have an achievement that made a reference to the infamous fanfic Doom: Repercusions of Evil
Now I've got another one
"Then John was a Zombie" would be like a 0G achievment for getting killed by a zombie just for shits and giggles.

 

[atomictoast]

"Go Outside: Spend more than 150 Hours playing - 0G" Halo 3, Halo ODST, CoD4, or MW2.

 

[L4Y Duke]

I don't think you quite get the point... - 5g - Pass 72-hour mode without leaving the helipad (Dead Rising)
Mr. Norris, I presume - 250g - Pass 72 hour mode with 2000+ kills without picking up any items (Dead Rising)

 

[Psychemaster]

Killing Floor (Let's pretend it uses XBOX achievements instead of Steam achievements for this)

- Screw the Zombies, I Have Money! (15g) - Buy every single weapon from the Trader over the course of a map.
- Double Decker (20g) - Shatter the skulls of 2 Fleshpounds with the same crossbow bolt.
- Sniper At Heart (25g) - As a Commando, get 20 consecutive headshot kills with the SCAR.
- Out of Sight, Still in Mind (15g) - Get 50 headshot kills on specimens behind explosion smokescreens.

 

[MultiPurposeBlue]

Metal Gear Solid 4:
Steven Seagal: slit 100 throats- "silver trophy"

 

[Kiutu]

For Oblivion
Clutter King: 0G
Collect one of every clutter item (spoons, pots, plates)

 

[NimbleJack3]

COD MW 2
77 GS - We're Ripoffs! - Get 5 Sticky 'Nade Kills in 1 game.(It's called We're Ripoffs because Halo 3 as an achievement for this and MW 2 has sticky nades).

Actually, InFamous has an achievement for 100 static bomb kills. It's called 'Oh, So You've Done This Before?'
The static bombs are almost exactly like plasma grenades.

 

[FallenJellyDoughnut]

"Deulerific Dickhead: Challange your friends to a duel 20 times in 2 minutes -10G" Borderlands

(Seriously this is what all my splitscreen matches in borderlands turn out to be)

 

[NuclearPenguin]

COD4 - Get the tent up! - Get 10 headshots without moving.

 

[FinalHeart95]

Halo 3- No Skill For U (0G)
Congratulations, you got a mythic map pack achievement while playing GRIFBALL.

Halo 3- Consolation Prize (5G)
Attempt to get Vidmaster: Annual and lose at least one friend from it

 

[Jake0fTrades]

A for Effort - 5G

Die 15 times in a row without getting a kill. (COD2-5)

 

[NimbleJack3]

Rainbow Six: Vegas 2
Doorcamper (Gold) - Reach Elite rank within a day of release
Empty Casings (Silver) - Fire 10,000 rounds
There Are Three Kinds Of A.C.E.S. (Gold) - Reach maximum level for all A.C.E.S.
Paper Cuts Scissors (Silver) - Finish the final scene firing nothing but a pistol
Status Quo (Bronze) - Play the game without changing the starting loadout

Star Wars: The Force Unleashed
Mirrorman (Bronze) - Finish the stormtooper module without moving
The Force Is With Me (Gold) - Upgrade all powers and stats to the maximum

Need For Speed Carbon
Corvette Pusher (Silver) - Overtake Darius on the first corner and win
Pimped Out (Bronze) - Fill the My Cars garage