The Walther P22 is plinking accurate with the five inch barrel- I put 10 rounds into 1.5 inchs at 10 metres with my first magazine full. The one I tried was perfectly reliable for 100 rounds but a friend has had so many jams he no longer brings it to the range. Very small grip well suited to small hands.
The Browning Buckmark is my all time favourite .22 auto, twenty years ago I shot one for the first time, I put ten rounds into a group I could cover with the ball of my thumb at twenty five metres with one, I've never beaten that group. The grip angle, sights and controls are all well located for my hand.
The Ruger MK II I had was perfectly reliable, I could never figure out how to dismantle it so I just cleaned the chamber with cotton tips and it was perfectly reliable. The trigger was quite heavy for a target gun and the grip angle never suited my hand. The safety catch was so stiff it took two hands to operate it. As I only used it as a range gun this wasn't an issue. Traded it towards a S&W 617
The Ruger 22-45 was also perfectly reliable, same safety catch issue, trigger was slightly better, front sight kept working loose and there was some movement between the grip and the reciever. Group sizes were slightly worse than the MKII.
S&W2206 was a perfectly reliable, lightweight and fun gun to shoot. grip was quite slim and well suited to small hands. Now discontinued.
S&W 617 six inch six shot full underlug revolver. Has had a problem with the built in safety lock refusing to disengage, it's too barrel heavy for me and I can't get used to the wide target trigger. Although a very well made gun I haven't warmed to it.
Beretta 92 practise kit: A .22 conversion unit for the Beretta 92, it includes a plastic ten shot magazine, an aluminium slide, steel barrel and recoil spring assembly. Fitted with target sights it is a fine tool for training and plinking, but not as accurate as a proper .22 pistol.
Ruger Single Six convertible revolver in .22 long rifle and .22 magnum. Most accurate .22 I have owned, it felt great it my hand and was great for training new shooters. The slow loading and ejecting cycle along with manually cocking the hammer each time allowed for a more methodic style of shooting. Wish I still had it.
Of the lot I would recommend the Buckmark first as it has a better trigger & safety than the Rugers, with the Single Six second and the Ruger MKII third.