Out of the choices given I had to say "other" because mine is close to some there but not quite.
I would go for my S&W 65LS. It is a K-frame .357 with a 3" barrel and fixed sights. For a carry gun I'd much prefer fixed sights to the adjustable sights of the 66, 19, 586 and 686. The .38spl M10/64 would be a close second since my 65 would usually be loaded with .38+Ps, though I'd prefer the added versatility of the .357 option. However, even in the .38spl I'd still prefer a 3" barrel if I could find one, with a 4" being the fallback.