Depends on your budget, the age of your children, their use (target, plinking, hunting small game, etc.). The Ruger single action 22's are well made and moderately priced. If you are considering a double action revolver, then take a look at the Smith model 617 or perhaps a Taurus. If you envision hunting in PA, stick to a revolver. Hunting rabbits with a 22 revolver is lots of fun!
The classic double action revolvers are the ones I lean toward. Smith made the Model 17 and 18 which are excellent. Colt made several models which have really seen some substantial increases in price in the last two years. Those models are the Officers Model Match, Trooper, Trooper Mark III and Diamondback if you limit your choices to post-1950 guns. I like the Trooper Mark III's, but they are heavy. Love the Diamondbacks as it seems just about everyone who likes Colts do these days based on the prices.
The Ruger SP101 is difficult to find in 22 these days as they are no longer made.
If the semi-auto 22's would be a consideration, my choice there would be a Ruger Mark II or III with 5.5" bull barrel. Nice pistol to shoot accurately and can be carried in the woods in a holster comfortably. Other ones are the Browning Buckmark, Walther P99, and one that Smith makes.
My first revolver was a H&R 999 22 revolver. They are around; many like them; I learned through experience that you should stick to Colts and Smiths for double action revolvers,
:banghead: 
