I own three S&W revolvers a 686 6", 340PD snub, a 66-7 4".
The 686 is an original "no dash." I've taken friends to the range so they could use it as their first gun (with 38 rounds). Even my best friend's fiance, who had never shot a gun, was staying in the black of the bull's eye at 10 yards with it.
The 66 is almost as accurate in 4". Got it for $150 after trade (had $400 on the tag, was a barely-used police turn in that had avoided being converted to DAO). However, it is much lighter and easier to carry, and isn't as muzzle heavy. I think the weight is pretty close to an SP101 and it has the longer barrel and one more round capacity. Extremely comfortable to shoot, as is the 686 - with neither you feel pain when shooting 357.
The 340PD is a 2 inch snub in scandium/aluminum. Has a steel barrel and cylinder. 38 out of it can hurt, and 357 is downright torture. A good last-ditch gun, but not for recreational shooting.
The 66 (stainless version of the 19) seems to be the best compromise between the larger L frame 686 6" and the J frame 340. K frame 3" are hard to get but are probably the best compromise, but I'm happy with the 4"
Tried Ruger. Not a fan of their current revolvers. Not able to say why, it's a "x factor" thing. I do like the Speed Six and Security Six revolvers - am cruising gun shows for one at this point.