I have a 6" 686 , 4"GP100 , 3" SP101 , so if I could justify the money a Python . But I would rather it be blue . IMO the blued Pythons were one of the nicest looking handguns made . I wouldn't even consider a new S&W 686 .
Kind of depends on your intended application.
Ruger GP 100-Built like a tank. This is the .357 I take into the mountains.
Colt King Cobra-Very concealable, easy to carry with the proper holster. Has that (imagined or otherwise) Colt mystique.
S&W Model 66-No dash, P&R. A true thorobred. Fun to shoot. Good for impressing your friends
But, I must say, the Ruger is a very tough act to follow.
Just kidding, I voted GP100, even though I have never owned one. I have always liked S&W in double action revolvers, but they aren’t what they once were. But I think they still make a decent gun. I haven’t seen a new Python, so I can’t say.
The Ruger has a long and solid reputation. I like the size for general use, and they are visually pleasing. The action has always seemed not quite as smooth as a Smith.
I have owned the SP101 with the 2 ish inch barrel. It was lovely with.38’s and LIVELY with.357! It was a great trail gun, but I wouldn’t enjoy it as a magnum range gun.