So I bought Modern Warfare 2 last Tuesday, and I've been playing it for quite some time now. So far, I am currently at level 25 and doing well with my collection of custom classes.

THE ONE I AM CURRENTLY USING IS AS FOLLOWS

NAME: Assault
PRIMARY: Bling'd M4A1 Thermal w/ HB (or a Rapid-Fire P90 w/ red dot)
SECONDARY: G18 Akimbo w/ Rapid-Fire
PERK 1: Bling (or Scavenger Pro)
PERK 2: Stopping Power Pro (or Hardline)
PERK 3: Steady Aim Pro (or Scrambler)
DEATHSTREAK: Painkiller (soon to be replaced w/ Martyrdom FOR THE LULZ)

As you can see, it's also one of my most debated-about classes, as I often find myself having trouble deciding which perks work out the best. Still, I might change my mind after I unlock some of the much-better weapons).