Unusual_Rex posted... Suppressors are awesome! I always use them. For me they are mandatory.
I would recommend using an assault rifle, two attachments, suppressor and ACOG or Thermal, have scavenger, hardline, and stalker, use a bouncing betty or claymore, then either smoke, concussion, or flash bang. For a secondary use the stingers.
For your killstreaks use helicopter, reaper, AC-130. Play domination, capture 2 points and then camp.
I always do this and get accused of cheating hahaha!
What really helps is posting in the correct console forums.
You know how on wii there are only 2 rates of fire (600 and 900) and all the auto weapons fit into them (bar mp7, which is 700)? Because of that, any weapon that has 600 rpm with rapid fire gets a 1.5 icrease, 900 rpm weapons get 1.0 increase, and mp7 gets a ~1.28 increase. So it is viable to use rapid fire on mp7, so I do. I'm not sure if I like silencer or rapid fire better (I like focus and stability, kind of meh on attachments).