Gears of War Cheats - Xbox 360

Infinite Ammo
Press [Up], [Down], [Up], [Down], [Left], [Left], [A], [B], [X], [Y], [A] during gameplay to get infinite ammo.

Achievements
Complete each achievement to get the allotted gamerscore:

A Dish Best Served Cold (30) - Defeat General RAAM on Hardcore Difficulty.
A Series of Tubes (20) - Host and complete 50 ranked matches.
Always Remember Your First (10) - Finish playing a versus ranked match.
Around the World (30) - Win a ranked match on every versus map.
Broken Fingers (30) - Defeat a Corpser on Hardcore Difficulty.
Can't Touch Me (20) - Win 10 ranked matches without losing a round.
Capital Punishment (20) - Kill 100 enemies in ranked matches with an execution.
Clusterluck (20) - Kill 3 enemies at once 10 different times (on any difficulty).
Commando (30) - Complete all acts on Insane Difficulty.
Completed Act 1 on Casual (10) - Complete Act 1 on Casual Difficulty.
Completed Act 1 on Hardcore (20) - Complete Act 1 on Hardcore Difficulty.
Completed Act 1 on Insane (30) - Complete Act 1 on Insane Difficulty.
Completed Act 2 on Casual (10) - Complete Act 2 on Casual Difficulty.
Completed Act 2 on Hardcore (20) - Complete Act 2 on Hardcore Difficulty.
Completed Act 2 on Insane (30) - Complete Act 2 on Insane Difficulty.
Completed Act 3 on Casual (10) - Complete Act 3 on Casual Difficulty.
Completed Act 3 on Hardcore (20) - Complete Act 3 on Hardcore Difficulty.
Completed Act 3 on Insane (30) - Complete Act 3 on Insane Difficulty.
Completed Act 4 on Casual (10) - Complete Act 4 on Casual Difficulty.
Completed Act 4 on Hardcore (20) - Complete Act 4 on Hardcore Difficulty.
Completed Act 4 on Insane (30) - Complete Act 4 on Insane Difficulty.
Completed Act 5 on Casual (10) - Complete Act 5 on Casual Difficulty.
Completed Act 5 on Hardcore (20) - Complete Act 5 on Hardcore Difficulty.
Completed Act 5 on Insane (30) - Complete Act 5 on Insane Difficulty.
Curb Appeal (20) - Kill 100 enemies in ranked matches with the curb stomp.
Dom-Curious (10) - Complete 1 co-op chapter as Dominic Santiago on any difficulty.
Domination (20) - Complete 10 different co-op chapters as Dominic Santiago on any difficulty.
Don't Hate the Player (10) - Finish with the highest points in a ranked match.
Don't Hurt 'Em (20) - Kill 100 enemies in ranked matches with the Hammer of Dawn.
Don't You Die On Me (10) - Revive 100 teammates in ranked matches.
Fall Down Go Boom (20) - Kill 100 enemies in ranked matches with the Boomshot.
For the Fallen (30) - Recover all of the COG tags (on any difficulty).
Honor-Bound (20) - Recover two-thirds of the COG tags (on any difficulty).
I Can't Quit You Dom (30) - Complete all acts in co-op as Dominic Santiago on any difficulty.
I Spy with My Little Eye (20) - Kill 100 enemies in ranked matches with the Longshot.
Is It a Spider (30) - Kill 100 enemies in ranked matches with grenade tag.
It's a Massacre (10) - Kill 100 enemies in ranked matches with the Chainsaw.
Mercenary (10) - Complete all acts on Casual Difficulty.
Mix It Up (30) - Win a ranked match in every versus game type.
My Love for You Is Like a Truck (30) - Defeat a Berserker on Hardcore Difficulty.
Pistolero (20) - Kill 100 enemies in ranked matches with a pistol.
Prison Breakout (10) - Completed tutorial level on any skill level.
Seriously ... (50) - Kill 10,000 people in versus ranked match total.
Soldier (20) - Complete all acts on Hardcore Difficulty.
The Money Shot (20) - Kill 100 enemies in ranked matches with a headshot.
The Nuge (20) - Kill 100 enemies in ranked matches with the Torque Bow.
Time to Remember (10) - Recover one-third of the COG tags (on any difficulty).
Zen and the Art of Reloading (10) - Perform 25 perfect active reloads (on any difficulty).
Zen and the Art Part 2 (20) - Perform 5 perfect active reloads in a row (on any difficulty).

New Achievements
These new achivements requires the new update and is only for Annex mode and the Hidden Maps:

All That Juice (30) - Win 20 multiplayer matches of 3+ rounds in any game type on the Process multiplayer map.
Green Thumb (30) - Win 20 multiplayer matches of 3+ rounds in any game type on the Garden multiplayer map.
Inconceivable (30) - Win 20 rounds of multiplayer matches in Annex by fewer than 5 points.
Mind the Gap (30) - Win 20 multiplayer matches of 3+ rounds in any game type on the Subway multiplayer map.
Nub Pwn3r (30) - Win 20 rounds of multiplayer matches in Annex by shutting out the opposing team.
Purdy Mouth (30) - Win 20 multiplayer matches of 3+ rounds in any game type on the Bullet Marsh multiplayer map.
THIS! IS! ANNEX! (40) - Complete 100 multiplayer matches of 3+ rounds in Annex and capture 3 objectives in each match.
You Down With E.P.I.C? (30) - Win a multiplayer match of 3+ rounds in any game type on 6 different downloadable maps.

Insane Difficulty
Complete the game on either Casual or Hardcore difficulty to unlock Insane difficulty.

Secret Gamer Pic
Complete the game on Insane difficulty to unlock a secret gamer picture. It has the Red Gear's Symbol behind Marcus Fenix.

Secret Gamer Pic #2
Unlock the "Seriously ..." achievement by getting 10,000 kills in ranked multiplayer matches to get that respective GamerPic.

Secret Gamer Pic #3
To unlock this gamer picture, you must finish playing any ranked versus mach. This picture shows Marcus running in the rain.

Secret Gamer Pic #4
Unlock the "THIS! IS! ANNEX!" achievement by completing 100 multiplayer matches of 3+ rounds in Annex and capture 3 objectives in each match on any multiplayer mode to unlock the respective gamerpic.

Gears Cereal!
On Act 5, when you are on the train and press the very first button you see, the berserker will magically appear. It will be expressed through a cut scene where it busts through a couple of box, and a lot of objects "explode" from these boxes.

If you manage to make it around the berserker, go to the very last car on the train, (the one the berserker appears on,) You will find a cereal box, I believe to be called "Gears Crunch." On the backside of these boxes, there is a fictional prize you could win (which happens to be a small fluffy pillow!)