Out of the ARs (15s & a 10), a couple of .22 rifles, a .22 pistol, some shotguns, some .38s, my Glock 23 carry piece, & one Mosin-Nagant I'd have to say that I would hold on to my S&W Model 13.
Black Betty is my favorite and the one gun I have that can do just about anything the others can do (although not as well, of course.)