I'm going to say the P90 due to its decent Irons and large capacity. I can see rapid fire and a kick proficiency being placed upon this gun making it insane. I have more faith in IW/SH in that they will balance the weapons as they did in mw2 regardless of the UMP which I felt was fine. Every game has a gun from each section that stands out but thats inevitable.

ASUS-12/SPAS-12 with Range Proficiency.

Though, pp90 is a high chance to. Bullet hose anyone?

Great names by the way I am enjoying this thread!

also one thing that's not mentioned here are bugged weapons/attachments on certain weapons that makes them better then perhaps intended,

since the ump from mw2 is mentioned alot, my guess is that the range of this weapon is broken. that's why slapping on a silencer makes no differ and stopping power isn't needed either. The ump, in my opinion, also has a questionable hit registration.

other examples are (same title) Fal with holo sight (adds damage) or P90 with extended mags (adds sprinting time, but that's been fixed I think)

Some weapons are just broken, problem is that it's usually not corrected.

The other problems are that those weapons and combinations get overused, but that's not fixable.