Looking at stainless firearms only -
A Smith 617 is, after all, a S&W Model 17 which is and always has been one of the finest .22 revolvers in the world. But the 617 suffers from that totally useless underlug which adds weight to a handgun that never needed it. If the weight doesn't bother you then the 617 is still top dog for a quality DA .22 revolver.
The S&W Model 63 in it's original 4" form or one of the earlier iterations, like the 5" model, is a great .22 revolver for packing. The current 3" model is still good but IMO not up there with the original. The only problem with the original is the red ramp sight is too wide for the rear notch, or the rear notch is too narrow, take your pick, but that's a small quibble. If'n I had my druthers I'd get the 5" model where they remedied that by putting a nice all black front sight on it to give it a very good sight picture, but those are pretty rare on the used market.
Have no experience with the new Ruger SP101 4" model but everything I've read shows it to be a typical Ruger. Tough, accurate enough, but not very refined in trigger pull.
The new Ruger Single Ten is a dedicated 22LR single action handgun so from what I understand they remedied the oversized bore of the convertible models which were sized for .224 .22 Magnum ammo, not the slightly smaller .22 LR. The longer 5 1/2" barrel gives it a nice sight radius so one should be able to do some decent precision shooting with it. Lipsey's also makes a 4 3/4" barrel stainless model. Other than that I don't know much about them.
Bearcats are neat but without an adjustable sight you are stuck with wherever it wants to hit which may or may not coincide where you want to hit.
