[darkgael]

How old was that thread? Just curious.
Very probably the most accurate handguns in any caliber are going to be single shots. The T/C Contender has a well deserved reputation for extremely good accuracy at distances well beyond what other handguns will do. It will outshoot virtually any revolver or semi. Forget rapid fire. The Encore, as well, is very accurate.
As for .22s, the most accurate .22s are those exotic target guns called "free pistols". (the Free Pistol is an Olympic shooting event, one of the International Pistol shooting events. It is 60 rounds fired at a target 50 meters away.)
There are quite a few good free pistols - all will outshoot any other type of .22 pistol at 50 yards/meters. They generally come with test targets that have amazingly small groups - one hole, not very ragged.
What distance are we shooting at for this thread? Up close, it may be hard to tell the difference. Stretch it out and quality shows. And ammo choice - especially with .22s - has a lot to do with how accurate a given firearm will shoot.
Pete