I pretty much just use my sniper created class.
Dragunov with no attachments, the M1911.45 with silencer attachment, and my perks include:
2 C4 charges(I'm this close to level 23 and then I'll switch to claymores.), UAV jammer, and Deep impact.
My favorite level is Pipeline, get me on that grassy hill and I'll be able top take out 2 or 3 people before someone finally rushes up behind me and knifes me, that's why I'm waiting for the claymores.
And before anyone starts with it, I don't camp, I'm always on the move, especially with that killcam thing, I also snipe mostly because most everyone and their uncle likes to use the martyrdom perk, and it doesn't affect you if your on the other side of the map.