without getting the AR, AK & SKS guys all worked up... IMO, the best carbine may not be a carbine anymore...
I'm not a big fan of the AR pistol, but if built & outfitted with quality necessesities, it has the potental to outperform the carbine... for civilian clearing "a" house use...
my FN 5.7 pistol with 3 - 20 round magazines with attached light & selected handloads likely falls into the same category...
after that my next choices would my 12 ga coach gun... after that would be either my 30 Carbine or an AR built around the 10 mm cartridge ( trouble there is I think only Olympic builds guns in 10mm right now , & quality could be questionable )
but I highly believe in the KISS concept my FN wears a light, my 30 Carbine a reflex sight, my SKS has been stripped down to basics, & accurized... it now shoots better than most, & I find I can reload with stripper clips faster than most can change a 20 or 30 round magazine on an SKS... I don't have an AK, but my new VZ-52 is bare bone functional
but honestly... if things go bump in the night in my home, my 1st grab is my regular carry S&W air lite 5 shot 44 special, & a Streamlight I keep with the guns, as I may not want the light attached to the gun, & I'm most comfortable & accurate with the 44