Right now I am using care package, stealth bomber and chopper gunner. Just thought it might be interesting to see what everyone else uses.

UAV, Harrier, Pave Low Currently 

I'm actually using the default ones still currently. I might drop UAV at some point, but I don't really get very high kill streaks anyways.

UAV, Supply drop, Pave Low.

UAV, Predator, AC-130. I find that I can usually use the first two to set myself up to continue the streak up to 11 and get the AC-130.

Supply Drop > Predator Missile > Chopper Gunner

UAV, Harrier, and AC-130.

Counter UAV.  Wasn't paying any attention to the others.  Since I don't live long.  Just like sprinting into their spawn area, dropping tactical insertion, whipping out my silenced striker and going ape shit on Friendo's face.  

Care Packace, Predator Missile, Attack Chopper for now.

Care package, first helicopter (need to change next unlock), and the emergency drop (which is amazing...four effin care packages)...for example I got emergency drop earlier today and got a turret, attack helicopter, harrier airstrike, and a UAV jammer

Currently using Predator Missile, Precision Airstrike and Harrier Airstrike. Once I get that Predator, I can usually get the other two rather quickly.

Counter UAV, Predator and Airstrike.

Care Package > Predator Missile > Harrier Strike
 
I use care package for potential additional killstreak benefits so it acts like a 4th killstreak. Predator Missile 'cause I like controlling the missile and blowing shit up. And Harrier Strike because its pretty much a combination of a airstrike and a helicopter.

right now I have:  care package, Harrier strike, AC-130.

Care package, predator missile, attack chopper

Predator, Pave Low, AC-130. Takes a while to get going, but once I get that missle there's no stopping the pain train!

HOW DO I USE KILL STREAKS?

Predator, Harrier and Pave Low.

UAV, Predator Missile, Helicopter. 

UAV, Sentry Gun (I play headquarters mostly), and Chopper Gunner

Default because they're the easiest to get, and the care package can give some nice rewards.  Could never go past even 6 kills in this game anyway.

• Care Package
• Predator Missile
• AC-130

predator, harrier, chopper gunner (the 11 kill one)
 
i just use other people's UAV's :O

seems to work pretty well, sometimes i'll get my five kills, then i'll try to get two from my predator, which gives me my harrier, then i only need 4 kills from it to get the gunner. And the gunner normally gets me like 8-10 kills. So from 5 i can suddenly go up to 20 -25 kills with like no effort lol.

 UAV,   Sentry Gun, Harrier    

UAV, Predator, Harrier

Switch between: Supply Drop, Harrier, AC-130 / Supply Drop, Harrier, Emergency Drop

usually i use Care Package, Predator, Harrier. Although sometimes i'll use UAV, sentry, or AC-130

Predator > harrier > ac130
 
 
Got a 38 kill streak with it, it's pretty nice. The predator usually leads straight to the harrier, which then usually kills 2 or 3 people, forcing me to only have to kill one more person to get an ac130. It's a nice set up.

Care Package, Predator, and Harrier. Although I`m thinking of swapping in chopper gunner or AC-130 next unlock. Will probably replace the predator?

Auto-Turret, Precision Airstrike, Harrier Airstrike

UAV, Supply Drop, and then the last is usually a Predator, Sentry Gun or Helicopter.

UAV, Air Drop, Predator

Predator, Harrier, AC-130H. If I can get the predator I can usually get to the AC-130H pretty easily since I almost always get the Harrier after a Predator. Unfortunately, when I do get a AC-130H I get so excited to use it that I get myself killed and can't extend my killstreak which is why I'm still only sitting at a 12 killstreak.

Harrier 
Chopper Gunner 
Nuke! 
 
:D

Harrier  
Chopper 
Nuke

Right now I'm using bullshit killstreaks to get emblems....Sentry Gun, Precision Airstrike and Attack Helicopter.....I usually use predator missile, harrier and pave low 

UAV, Predator Missile, Harrier

For most games - Pave Low, Chopper Gunner, Nuke. 
 
For Search and Destroy - UAV, Predator Missile, Harrier.

I change it up everyday.

I just got back into Headquarters.  It's pretty fast-paced so I set them low (3-4-5) with UAV, Counter UAV, and Sentry.  When I'm playing ground war I crank them up to (5-7-9 or 11) with Predator, Harrier and Chopper Gunner.  These have always worked pretty well.

at the moment  predator, harrier, chopper gunner. Im trying to get all the emblems i only need 3 more.

Predator, Harrier, Pavelow.  
 
If the map is big and open, I usually change the Pavelow to a Chopper Gunner.

predator, harrier, AC130
also when im feeling cocky i set up harrier, AC130, nuke
i havent gotten a nuke yet, ive gotten really close though

Predator, Harrier, AC130

It varies but I mainly use UAV, Counter, Harrier or UAV, Harrier, Chopper gunner. Never once have I turned on nuke, sentry gun, stealth bomber or EMP.

Because I tend to die quickly:
 
UAV, Counter-UAV, Pred Missile :)  I think counter-UAV is an underrated perk, but of course there are far better ones out there so I can see why no one uses it.

UAV(whoever thinks UAV and/or Counter UAV is a waste is an idiot), Predator, Harrier usually  
or if I'm really bored 
Harrier, Chopper Gunner, Nuke