My favorite semiauto plinker is a Ruger MkII 22/45 with a 4" bull barrel. The manual of arms is very similar to the 1911 .45 pistol, so using it reinforces muscle memory for the larger gun. Takedown on this one is quite easy, much smoother than on most of the steel-frame models. Therefore easy to clean in a few minutes.
Although I have a couple of MkIIIs, I'll never buy another. The loaded cartridge indicator and the magazine safety make the takedown way too complex and neither device really serves an important function if you're aware and observe the standard safety precautions. The more gadgets, the more possibility for failure. I've also found the quality control on the MkIIIs to be spotty. If you have or can find a MkII, those are the guns to get.
John