PP90m1 has shorth enough mags to use Rapid Fire id rather use extended mags rather than Thermal scope

There is no best gun it depends all on skill/play style. Are you a camper, rusher, quickscoper, tanker(riot sheilders) & also, trigger finger speed makes a big difference if its slow that will opt out all semi auto guns. some guns do have more accuracy than others but youll do best with whatever your comfortable with. like for me i use pm-9 because i like fast pace killing.

Most powerful? I would have to say type 95.. it's a one shot kill every time. so powerful. so overpowered if i might add..

but favorite gun wise? i would have to say is that it's probably the acr, mp7 silenced, or one of the snipers, even though i suck at using them.

but favorite guns of all time have to be mp5 and g36c from cod4, so smooth and powerful. actually every gun from cod4 is a candidate. and the PTRS from WAW, which is probably the best sniper to ever enter the call of duty series. or maybe even the mp40 from waw as well.