If you like running round getting loads of kills or you go for the win
These classes are the best

Rushing Class 1) MP7 - Extended mags with Focus secondary any-
Perks - Extreme Conditioning , Assassin , Dead Silence , frag grenade and concussions

Holding down an area can be hard with the wrong class not with this

ACR - Red Dot with impact , secondary Mp9 extended mags , semtex , concussion
Perks - extreme conditioning , qiuckdraw , dead silence

If you have turtel beachs you might wanna put sitrep pro on to sound hore with this perk pro u may hear
People with dead silence on

And last of all if u love an old shotgun battle

The Striker with damage an extended mags with mp9
Perks - extreme conditioning pro , blast shield pro and steady aim

These classes with all the perks pro are amazing

These are the best classes I personly think
Have fun killing guys.