Scientifically Best Weapons

The following is not based on personal preference.

Assault Rifles

#1:  ACR

#2:  SCAR-H

Sub Machine Guns

#1: UMP 45

#2: Mini-Uzi

Light Machine Gun

#1: AUG HBAR

#2: RPD

Sniper Rifles

#1: Barrett .50 Cal

#2: Intervention

Machine Pistols

#1: M93 Raffica

#2: TMP

Shotguns

#1: Spas-12

#2: M1014

Handguns

#1: M9

#2: USP 45

Launchers

Stinger for anti-air, RPG for infantry.

Killstreaks

Care packages great for people who honestly can't get higher killstreaks.

At earlier levels to compete with the higher rank players always have UAV as your first killstreak. This will help you team win since they will know most enemy positions and you will even get points for activating UAV's.

Tactical Nuke killstreak combo

Harrier Strike, Chopper Gunner or AC-130, Tactical Nuke

Normal killstreak combo (11)

Predator Missile, Harrier Strike, Chopper Gunner/AC-130

Normal killstreak combo (7)

UAV, Predator Missile, Harrier Strike

Casual gamer killstreak combo

UAV, Care Package, Predator Missile

Knifer killstreak combo

UAV, Counter-UAV, Predator Missile

Team player killstreak combo

UAV, Counter UAV, Sentry Gun/EMP