Howdy
The Smith and Wesson Model 17 (and its predecessor the K-22) has always been the gold standard of 22 rimfire revolvers. These are double action revolvers. Also available today in a Stainless version as the model 617.
Since your question was specific to single action revolvers, the Ruger Single Six has always been a quality 22 rimfire revolver. Blued Single Sixes have always been all steel except for the grip frame and ejector rod housing, which are anodized cast aluminum. Stainless Single Sixes are all Stainless, including the grip frame and ejector rod housing.
These are the old Three Screw Single Sixes, you can see the different color of the anodized aluminum grip frames. Three Screw Rugers have not been made for many years, they did not have a transfer bar in them and could only be safely loaded with five rounds with an empty chamber under the hammer. Since the 1970s, all Rugers have a transfer bar inside, so they can all be safely loaded with six (or 9 or 10, or however many rounds it takes to fill the cylinder.) You will notice that one of my old Single Sixes has an adjustable rear sight, the other two came with a rear sight that was adjustable for windage by drifting it to one side or the other. They were not adjustable for elevation. Most Single Sixes today come with adjustable sights, although I notice that one model comes with fixed sights, that are not adjustable for windage or elevation.
The Ruger Wrangler is a brand new entrant in the single action rimfire market. Clearly designed to compete with the Heritage 22s in price. The Wrangler frame is aluminum, the grip frame is cast zinc alloy. The cylinder and barrel are both steel. The Cerakote finish on the Wrangler is one way the cost is kept down, it is a less expensive finish than a polished blue finish. The Wrangler is only chambered for 22 Long Rifle, it does not come with an auxiliary cylinder for 22WMR. I don't own one but I have had a chance to shoot them and I was impressed with the quality. I am not impressed with the quality of the Heritage revolvers.
I will probably not be buying a Wrangler simply because I already have my old Three Screw Single Sixes.
Incidentally, the Single Six was introduced in 1953. Colt had stopped producing the Single Action Army in 1940 at the start of WWII and had no intention of re-introducing it when the War ended. Colt figured there would not be much demand for the old design, and weak sales prior to WWII seemed to bear that out. What Colt did not realize was that after WWII GIs would be returning home, and many of them would take advantage of the GI Bill to get a college education and buy their first homes. And a lot of those homes would have brand new television sets in them, and the likes of Hoppy, and Roy, as well as Matt Dillon and all the other TV cowboys would be galloping across living rooms all over the country. When the Single Six showed up in 1953 all those TV sets had created a pent up demand for a single action revolver and Ruger had a hard time keeping up with the demand. In 1955 Ruger introduced their first centerfire single action revolver a 357 Magnum Blackhawk. Colt saw the handwriting on the wall and reintroduced the SAA in 1956.
Personally, I prefer a revolver to be a six shooter, including my rimfires. I do have a ten shot S&W Model 617, I bought it used because I was taking part in a steel match and had to fire 8 aimed shots in 15 seconds. Could not do that with a six shooter. I don't shoot that match anymore, so the 617 does not get out much. For me, putting more than six shots in a revolver cylinder tends to make me go through way more ammunition than I need to.
But that's just me.
