Call of Duty: Modern Warfare 2

...The Harder They Fall -
1bullet2kills - 1 collateral damage kill
1st Lt. - earned by leveling up
1st Sgt. - earned by leveling up
2fast -
30 Something -
Absentee killer - get a game winning kill cam with a sentry gun
Accident Prone - kill yourself 5 times
Airborne - call in 3 pav lows
All Pro - Headshot 2 + Enemies with 1 bullet
All Your Base -
Angel of Death -
Armed and Dangerous -
Avenger - Killing The Enemy That Killed your Teammate within 3 seconds.
BAM! -
BOOM! Headshot -
Backstabber - Knife a Enemy in the back
Big Brother -
Bite the Bullet -
Blindfire -
Bling Bling -
Blood Brothers -
Blood Money -
Blunt Trauma - 2 kills with Riot Shield
Boilermaker -
Bombshell -
Booyah! -
Bow Down - Have the highest K/D ratio at the end of a game
Broken Arrow -
Catch Shrapnel - get 5 claymore kills
Charity Case - call in 50 Care Packages, Sentry Guns or Emergency Care Packages -
Chick Magnet -
Cloak and Dagger -
Cobra Strike -
Cold Steel -
Commander - earned by leveling up
Companion Crate - call in 25 Care Packages
Completely Numb - Take enough damage to normally killl you with painkiller activated.
Concussive Barage -
Crackin' Skulls -
Cruelty - Kill an enemy, pick up his weapon, then kill him again with his own weapon
DZ Clear -
Deadline -
Destroyer -
Death from above - get a game winning kill cam with an AC130
Devestater - kill every member of the enemy team (Tango Down challenge)
Dishes are Done -
Dish the Rock - 10 Assists in a Game or Most Assists in a Game
Disruptor -
Double Down -
Drifter - destroy 1 car
Drone killer - get a game winning kill cam with a predator missile
Droppin' Crates - Get a Game winning Killcam by dropping a crate on the enemy
End of the Line -
Enemy of the State -
Enemy with Benefits -
Epic -
Excalibur - 100 Knife Kills
Explosive Ordinance -
Fire and Forget - Call in 25 Sentry Guns
FNG - start out with this
Faceoff -
Finishing Touch - Get a Game winning Killcam with a precision Airstrike
Frag Out - Most Frag Kills in a Game / Triple Kill with a Frag
Flying Tank -
Flyswatter - shoot down a chopper
Full Throttle -
Gen. - earned by leveling up
Get Real - Win 1 Game of Team Hardcore Deathmatch
Get to the Choppa! -
Ghilie in the Mist - one of the three 'One-shot, one-kill' challenges
Ghostrider - get 75 kills with the AA-12 shotgun
Givin' Static - Call in X number of Anti-UAV
Global Thermonuclear War - call in 2 tactical nukes
Godhand - Calling in 2 Ac-130s in one game
Grassy Knoll - spend a certain amount of time prone
Group Hug - Kill Multiple Enemies with a Semtex Stuck to 1 of them
Hair Trigger -
Hard Target -
Hard to Kill - get 2 kills on Last Stand
Hardcore Only - Win 10 HC TDM games
Headrush - 5 headshots with an SMG
Heartbreaker - get 15 claymore kills
Hello "Fired!" -
Hello "Its Personal" - kill someone with a throwing knife after wounding them
Hello "My Name Is" -
high def - get a game winning killcam with a chopper gunner
High Caliber -
Highlander - Go a full length match without dying
Hijacker - grabbing enemy teams care packages
Hot Shot -
ID Thief - get a payback kill with Copycat enabled
Impaler - stab 5 people
Intergalactic - Playing Sabotage
Invisible - Silenced Weapon, Ninja and Cold Blooded
Iron Lungs - 200 Kills Steady Aim Pro
Jack-in-The-Box - Kill 5/10 enemies within 5 seconds of spawning via Tactical Insertion -
Joint Ops - Kill Someone Within a Smoke Filled Area
Jump Jet - call in 5 harrier airstrikes
K Factor -
Klepotomaniac - Kill 3 enemies with 3 different weapons in a single life
Last Resort - Get a Last Stand or Final Stand Kill in Game Winning Killcam
Live Long.. -
Living Dead - for surviving and getting back on your feet after you've been downed to final stand
Lone Wolf - Win a Free For All Match
Low Profile -
MOAB -
Mad Man -
Maj. - earned by leveling up
Martyr - get 1 kill with martyrdom
Mastadon - Have Elite Challenges Unlocked and get a 5:1 K/D Ratio
Mastermind - get 25 kills with the aa12 shotgun
Misery Loves Company - Kill yourself and 1 enemy by cooking a grenade without throwing it
Money Shot -
My Lil' Pwny -
NBK - get 3 Longshot kills in one life
New Jack - ATM Challenge Payback with a Throwing Knife
Ninja -
No. - Kill Someone Cooking off a Grenade before they Throw it.
Noob tuber - kill an enemy with a grenade launcher without detonation (Ouch challenge)
Not in the Face! -
OG - get a game winning kill cam with an attack helicopter
OMFG -
OMG -
Omnicide -
Omnipotent - Have the highest K/D ratio at the end of a game 25 times
One Inch Punch - get 750 kills using Sleight of Hand
Overwatch -
Owned - Get a Riot Shield melee kill in Game Winning Killcam
Ouch - Kill an enemy with a rifle-mounted grenade launcher without it Detonation (Direct Impact)
Perfectionist - for emptying a sniper clip without missing a shot (Hit an enemy with every round you fire from that clip).
Philanthropist -
Pineapple Express - get 25 grenade kills
Plane Whisperer -
Plastique - get 5 kills with C4
Popoff -
Preemptive Strike -
Pro Gambler -
Protect and Serve -
Public Enemy -
Pushin' Daises -
Pyromaniac - destroy 2 enemy equipment
Rainmaker -
Rain of Fire -
Re-zero -
Reign Down - 5 Predator Missles
Rejected - Pick up an enemy tactical insertion
Reloaded - Have the most reloads in the match
Remote Viewer - 5 Bullet Penetration Kills
Rival - kill the same enemy 5 times in a single match
S.S.D.D. - earned by leveling up
SBD -
SIGINT -
Sarge -
Sgt. - earned by leveling up
Share Package -
Shot Down -
Sidekick - Get 3 Kills with Your Secondary Weapon
Silent Strike -
Skeet Shooter - Kill Someone That is Jumping In Mid-Air
Sky Commander -
Slow But Sure - Kill 1 enemy while being stunned by a stun grenade
Smash Hit - 5 Kills with the Riot Shield
So Baked -
Solid Steel - survive (30) grenades with blast shield
Speed Demon - Get 25 kills with Slight of Hand equipped
Spy Game -
Squawk Box -
Starfish Prime -
Stickman - Stick a Semtex to the enemy in a game winning Killcam
Straight Up -
Streaker - do the "fearless" challenge (kill 10 ppl without dying)
Stun Gun - kill one enemy while being stunned by a stun grenade
Submit to Authority - 15 bullet penetration kills
Suppressor -
Sureshot -
Surgical -
TacDel -
Ta-Da! - 25 kills within 5 seconds of spawning with Tactical Insertion
Take a Stab -
Tango Down -
Team Player - Call in Care Packages and Allow Team To Take it
Techno Killer - get a game winning kill cam with a stealth bomber
Transformer - get a game winning kill cam with a pav low
The Bigger They Are.. -
The Inciser -
The Legend -
The Mad Bomber -
The Mastadon -
The Watchman - calling in a (X) number of UAV's
Thermal Nuclear War - Get 3 nukes
Time is Money - that you get after getting 5 paybacks with semtex.
Time on Target -
Trackstar - Marathon Pro
True Liar - Get a Game Winning Kill with a Harrier
Unbreakable - Block 1000 bullets with the Riot Shield
Voyeur - call in 25 UAVs
Wargasm -