if you had said 357 ("only") grail gun, as in out-of-production collectible class
I suspect there would be a lot more votes for the Colt Python or a S&W model 27 or pre-27, or maybe a classic Dan Wesson
but for me, 6" barrel S&W 19/66 is '"it", in 38/357
Like a lot of folks, I don't run a high round count of 357s thru my pair of 66s
They do see a lot of 38 sp range fodder, and I think of them as pert near perfect 38+P revolvers
(perhaps like someone else above, I mostly reserve my 357 ammo supply for lever action carbines)