My 1956 Single-Six is the best single action in the world. Of course I'm somewhat biased in my opinion. I've been shooting this beautiful Single-Six since I was 7 years old, with my Dad of course. I can hit anything with this old flatgate. The original owner worked tool and die for Westclox, a now defunct clock and watch company. He had access to thousands of different springs, and he replaced two springs which brought the trigger pull down into ounces of pull. The original springs are still safely taped to the inside of the grip panels. I love those old black plastic / rubber grips. The checkering still has some bite to it, but part of the black eagle emblem paint is worn away.
When Ruger came out with them, he bought one with adjustable sights and wood grips, and sold the 1956 to my Dad for $65. For years after that he gave my Dad a standing offer of $100 to buy it back, and luckily Dad never buckled. Bruce could never get the newer Ruger to shoot nearly as accurately as the old one, and every time we went to his farm to shoot he would just sigh every time his first shot went exactly where he had it aimed.
I don't have any children, so I will leave it to one of my Brother' kids when I'm dead and gone. Until then, I will just smile as my first shot blows the little .22 box that I use as targets clean off of the board that I line them up on. I seldom miss from 25 yards because you almost don't need to aim with the sights. You can just feel when you have it lined up. God I love that little Single-Six, and every time I take it out back I feel as if my Dad is back there with me. A little part of Dad is still in that little gun, because he loved it as much as I do. Bill Ruger really got it right the first time.
As soon as I turned 18 I bought a brand new 200th Year stainless with the 6 1/2" barrel. I still have it, and it's still like new after thousands of rounds. My Dad used to shoot mine, and he liked it. I think that he was proud that one of my first adult purchases was a Ruger Single-Six. I know that he didn't like it as much as his, but he liked shooting the .22 magnum quite a bit. I'm currently turning my stainless into a scoped pea shooter now that the Weigand mount is available and I don't have to alter it. I just ordered a one piece Hogue grip from a gentleman on this forum, so now I may be able to shoot as accurately with mine as with the flatgate. The only way to catch up with Dad's Single-Six for accuracy is to put a scope on it. That old '56 is just an amazing piece that is priceless to me.
In my opinion the best single action is the Ruger flatgate Single-Six hands down.