Sniper:
Barrett .50 Sniper Rifle
Colt M1911 .45
x2 Claymores
Stopping Power
Deep Impact
x1 Smoke grenade
Assault:
G36C Red Dot Sight
Gold D.Eagle (It doesn't do anymore damage than the standard D.Eagle, but it just looks AWESOME)
Bandolier
Stopping Power
Deep Impact
SMG (I call it CQC though):
MP5 w/ Silencer
M1014 or whatever that semi-auto shotty is
x3 Stuns
Overkill
Dead Silence
That's just my favorite setup.
I use the Sniper class for maps like Creek and Crossfire, the SMG (CQC) class for Shipment, Killhouse, other maps like that, and the Assault class for just about everything (I don't use the nade launcher, it sucks balls and it is only for NOOBS!)