upgraded wunderwaffe and colt pistol (the best upgraded gun ever!!!!) with juggernog/speed cola/quick revive (if in co-op above the bowie knife)
upgraded wunderwafffe and Ray gun with juggernog/speed cola/double tap (solo while run and gun)
Those are actually very bad combinations. The upgraded colt just doesn't do it for me, and the wunderwaffle is a suicide machine. Having the Ray Gun instead of the colt is a little better, but when you have to reload you go bye bye