Lately I've been using the AK47 with Scavenger Pro, Stopping Power Pro, Ninja Pro. Claymores and flashbang, secondary either Akimbo Magnums or Magnum with tactical knife.
For game types where I have to defuse or capture quickly, Marathon Lightweight Commando with a Mini Uzi. Semtax and stun, secondary Akimbo G18s.
Then I have a Sniper class, that I use rarely.
that first one is a lot like my favorite class. i use the M16 mostly though. still haven't unlocked it again. don't think i'll prestige again. 7 custom classes is enough.