I find the Walther P22 to be a very good around .22 plinker. I like to go shooting with my wife and we found her thumb is too short to operate the slide release. The P22 is the only .22 pistol she feels comfortable operating and shoots well. As a result, she has influenced several of our (female) friends attempt shooting. Two of them have purchased the P22.
I also find it to be very accurate, easy to assemble, and very affordable($350-375 new). It comes with two mags, two barrels, and interchangeable front sights. It also shares many of the same features as the P99 so the transition from practice to carry is smooth.
Gilgamesh