I have a lot for many different situations. My two favorites, though, would be my Stealth class and my Rifleman class.
Stealth:
Silenced MP5
Silenced USP
Bomb Squad
UAV Jammer
Dead Silence
Rifleman:
M16A4 Carbine (ACOG Scope)
M14 (Red Dot Sight - Working for ACOG)
Bandolier
Overkill (duh)
Deep Impact
Both are simple, but effective. I've pulled out some major games in Bloc with my Stealth class, and Overgrown is really easy with my Rifleman class.