Call of Duty: Modern Warfare 2/Intimidation

Challenge	Rank Unlocked	Requirements	XP	Title	Emblem	Tactics
Omnicide!		Kill the entire enemy team (4 or more people) within 10 seconds.				Use an AC-130 or Copper Gunner to do this easily.
Wargasm		Get all 3 of your killstreak rewards within 20 seconds.	3,500			Pick 3 Killstreak rewards close together and sue them (UAV, Counter-UAV and Predator Drone is probably best as these are required for further challenges in this category.)
The Bigger they are...		Kill the top player 3 times in a row.				If they are a camper then try to find them, if not then play normally, it is fairly easy to earn this normally in a long match.
...The Harder They Fall		Kill the top player 5 times in a row.	5,000			〃
Crab Meat		Kill 10 enemies with a single killstreak.				A Chopper Gunner or AC-130 should do this fairly easily.
Ultimate Sacrifice		Nuke the enemy while your team is losing	10,000			You can wait with your nuke until the enemy team is a bit ahead then win and get the challenge.
The Denier		Kill an enemy before they earn a 10 or higher killstreak reward.	5,000			Eventually you'll kill someone at the right time to get this.
Carpet Bomb		Kill 5 enemies with a single airstrike.	5,000			Use Danger Close Pro to increase the power of the airstrikes so you have more chance of getting this.
Red Carpet	64	Kill 6 enemies with a single Stealth Bomber.	5,000			Use Danger Close Pro to increase the power of the airstrikes so you have more chance of getting this.
Grim Reaper	64	Kill 5 enemies with a single Predator Missile.	5,000			Use this at the start of a match after swapping sides for more chance to get this Challenge.
No Secrets	64	Call in a UAV 3 times in a single game.	2,500			Equip UAV and Hardline and you should get this in a game. Possibly die after getting the UAV.
Sunblock	64	Counter the enemy's UAV 3 times in a single game.	2,500			Equip Counter-UAV and Hardline and you should get this in a game. Possibly die after getting the Counter-UAV.
Afterburner	64	Call in an airstrike 2 times in a single game.	2,500			Equip an Airstrike and Hardline. Possibly die after getting the Counter-UAV.
Air Superiority	64	Call in a helicopter 2 times in a single game.	2,500			Equip an attack helicopter and Hardline. Possibly die after getting the Counter-UAV.
MG Master	64	Get a 5 kill streak while on a mounted machine-gun	2,500			Get on a Mounted Machine-gun in Wasteland for the best chance to get this achievement.
Slasher	64	Get a 3 melee kill streak without dying	3,500			Equip Marathon, Lightweight, Commando and A Tactical Knife, then go around and melee people you see, maybe hide behind corners waiting, don't stay out in the open for long though.