Probably my bolt action .444 Marlin.... Hits 'em like a sledgehammer.
I also like my AR when I want to take multiples out of a sounder, my bow when I want to be quiet, an my .270 WSM when I want to hit them with a larger bullet going over 3,000 FPS.
Basically, anything will do the job if you are accurate. Look at some gunships and find a gun that you like and make it your favorite. I will say that hunting them with a handgun is a completely different challenger, and I would look into the ranges that you will be shooting before setting your heart on that.
I forgot to add, 12 ga slugs also work quite well for leaving them DRT.