New Guns: The best choices are the Smith & Wesson Model 617 in either a 4 or 6" barrel. Smith also makes the Model 317 which is their light (and small) aluminum framed J-frame in 22LR and 22WMR. This is primarily a short barreled pocket type gun. Great little gun, but the larger 617 is a better all around gun to shoot. There are also choices made by Taurus as well available. Ruger makes their Single Six and Bearcat single action 22 revolvers. I'd choose the Single Six if you want a single action over some of the "other brand" revolvers available.
The next tier of firearms are made by folks like Heritage Arms, Charter Arms, and Rossi. They tend to be less expensive and a lesser product than the above mentioned firearms.
Used:
I highly recommend one of the following 22 double action revolvers: Smith & Wesson Model 17 or 18, or the smaller Model 34's, Colt Trooper Mark III, Colt Diamondback, Colt Officers Model Match, or the Colt Trooper. The least expenisive of the Colts is the Trooper Mark III. Spend the extra money and buy one of the above revolvers. You will not regret it.
Single Actions Used: Colt New Frontier or Peacemaker or Ruger Single Six. The Colts are more expensive, but worth it if you can find one.
There have been many different models made by other companies. They include Taurus, Ruger, Charter Arms, Rossi, High Standard, Harrington & Richardson. Generally a lesser product than Colts or Smiths, but serviceable for the most part.
Best advice for TODAY (quality and price): Buy either a Colt Trooper Mark III in 4 or 6" barrel length or Colt Officers Model Match, OR Smith & Wesson Model 17 (6" barrel normally, but some 4" available) or Model 18 (4" barrel). On new production, go with Smith Model 617 in either 4 or 6" barrel. (This is the stainless steel version of the older Model 17 or Model 18 (K-22) which you hear so much about as being the best 22 revolver for the money. Spend the extra $$ on a well made 22 revolver and you are likely to never loose money if you sell it or you'll have a great revolver for the rest of your life and probably your children's and grand children's lives.
XavierBreath: Great post and good advice. The wear issue is significant as many of these revolvers are being purchased these days as collector pieces. That especially applies to the Colt revolvers which is why the price has been driven up in recent years. The Colt Diamondback is also a fine choice if you can find one that has a little finish wear to take it out of the collector status ranks.