Pretty much all mine are defense-class firearms. I have only a couple of "plinking" guns, and no "target" guns.
Accuracy, for me, is as much based on my ability with the gun as it is the gun's construction.
Of those I currently own, the one I am most accurate with is probably either my Ruger Police Service Six (.357 Magnum, but loaded with .38), or my Bersa Thunder 380. It seems I can shoot them both close enough together in aim as to be equal in my hands. My Ruger Mk-II is probably up there, too, but I'll be honest here; I haven't fired it much in the last several years to recall.
The one I have known myself to do the best with was the sidearm issued to me by my first LE employer, a S&W M67 revolver, especially after I upgraded the stocks.