I have several .22 Fun Guns.
First and foremost is my Ruger MKII Stainless 5 1/2" Bull Barrel. This Ruger was bought new by my late brother and after his passing I purchased it from my Sister in Law. Since it was a special gun to me I decided to make it more special. I had it drilled & tapped in the same hole pattern as the Ruger MKIII's. I also added the following:
Volquartsen Custom Target Sear
Volquartsen Custom Extended Bolt Release
Clark Custom Guns Steel Ruger Trigger
Clark Custom Guns Ruger Grips
On Targer Guns Blast Shield
Weigand Scope Base
Bushnell Trophy Red / Green Multi Reticle Electronic Sight
Next up would be a Ruger 10/22 that I bought from a buddy of mine. When I bought it it had been sitting in a barn for a couple years. Yes it took quite a bit of scubbing and cleaning. The first modification was to have the Factory Carbine Barrel Shortened to 17" (cutting off the front sight in the process). I then had the diameter of the barrel immediately in front of the V Block Dovetail in the Barrel turned down so I could slip a Green Mountain Non Vented Barrel Shroud over the Barrel. I did a trigger job on this Ruger myself and had the headspace set on the bolt, the firing pin pinned and chamfered / radiused the rear bottom face of the bolt. I then set it in a ProMag Archangel 556 Stock which I also modified by adapting a DPMS Carbon Fiber Free Float Tube to the Archangel and I replaced the Archangel Buttstock with a MagPul CTR 6 Position Collapsable Buttstock.
Yet another one is my Custom Ruger Charger. This one has been a work in progress for quite some time now. I actually bought a Ruger Charger and promptly sold the factory Barrel and Stock. I then sent the Receiver, Scope Base and an ALuminum Trigger Housing off to be done in Norrells "Stainless" Moly Resin. I then fitted the receiver with a KIDD 10" Matte Stainless Bull Barrel. I had the headspace set on the bolt, the firing pin pinned and chamfered / radiused the rear bottom face of the bolt. foe the Trigger I sent the Factory Trigger to TT Shooter for one of his Precision Trigger Jobs. I outfitted this with a Burris 3x12x LER Handgun Scope with Fine Plex Reticle and Target Turrets. The stock is a 10/22 Carbine Stock that with the help of my local gunsmith we transformed it into a Charger Handgun Stock with lots of work and modifying the stock so we could attach a T/C Contender Pistol Grip to it.
If I want to get serious about printing nice tiny groups with a Handgun the above Custom Ruger Charger gets the nod.
Lastly I would have to say that after my first range session with it my new Advantage Arms Glock 17/22LE .22 LR Conversion Kit for my Glock Model 22 is going to rank right up there with other favorites.
There are others also but the above are the ones that get the most use.