I own a wide variety of 22s, including a 22A, buckmark, 22/45, 1911-22, M&P22, etc. The 22/45 would be my choice. That's saying a lot being I am NOT a big ruger fan but the these little 22s are the 1911s of rimfire. All kinds of aftermarket mods available. Would highly recommend the volquartsen trigger kit.
The GSG, or Sig, 1911-22 is a fun 22 . Great little firearm that can be tricked out as well. Surprisingly accurate. A lot of 1911 interchangeable parts. On the downside, the slide finish is junk and you NEVER want to dry fire it even when using a snap cap, else you'll break the firing pin. I sent my slide of for cerakote and have worked the action to a very acceptable trigger.
I like my M&P 22. Trigger pull is very heavy though and no way that I know of to fix that.