User blog comment:Darthkenobi0/What do you recommend in Modern Warfare 2?/@comment-1079585-20100916012833

FAMAS w/ SP (unless you're using an RDS or Holo, then use M16 w/ Holo)

SCAR w/ Scavenger and Extended Mags is insane.

TAR-21

FAL w/ Holo and SP

ACR

AK-47 if you're good with it

UMP

P90 w/ SP if you want a break from the UMP and something that is better for CQC

RPD or AUG HBAR, probably w/ SP

Maybe the MG4 w/ Bling, Grip, and RDS if you are into that sort of thing

Barrett w/ SP

WA2000 w/ silencer and SP

M21 w/ SP

M21 w/ silencer and CB

And yeah, those are basically all of the primaries worth using in the game.