For me, it is the 4 inch S&W 586. Mine is an early production, 3 digit serial number gun. It was my duty gun back when we carried revolvers. We used to be able to pick up 500 round boxes of mild 38spl SWC reloads from the department range, and I did, every week. Quite a few Remington 357 mag 125 grn hollow points as well.
I have no idea how many rounds thru that gun, but I figure it was about 500 plus per week, double action, for about 3 years. Had to send it back to Smith twice to be "tuned up" as I had managed to shoot it loose. The double action was as slick as oiled glass, and I could not miss with that gun. I almost cried when they made me retire it for a 9mm auto.
Shot my first handgun deer with that gun, as well as a black bear at about 15 yards. I don't know who was more surprised...lol
Still have it, and often carry it in the woods while bumming around.
Larry