I'm going to pick up a 22 pistol tomorrow to run my AAC can on and I can't make up my mind on which pistol to get.  I'm considering a walther, sig and a ruger.  What's the consensus on the best 22 pistol?

I would go with the walther

Out of all of them - i liked the Ruger threaded with the Iron sights.

I liked the factory threading vs an adapter or third party barrel - I also liked the sights on the Ruger better than the P22

Stopped looking once I found the factory threaded Ruger 22/45 with the optic rail.  Started out with a Buckmark with a barrel threaded by my smith and also shot a friends  P22.  Lovin' the Ruger.  

I've shot other people's P22s using my Spectre, and wasn't impressed with the P22 as a shooter in my hands.
However if I was going to carry a P99/SW99, I think it would make a great practice gun and a very convenient suppressor host. It's fun, but not the .22 pistol I'd pick to hit targets at 25yds with.

The Sig I'm assuming is a Mosquito, which I have not shot suppressed. I'd pass. I briefly worked with a guy who was a local Sig dealer and was not impressed by the number that came back with problems. My short experience is statistically insignificant I'm sure, but it biased me personally.

Ruger MKI/II/IIIs are just great target pistols: good triggers, good ergonomics for shooting well, tough as nails. About the only downside is that they don't replicate the feel of most centerfire pistols if that's a concern to you. The barrel/upper receiver needing an FFL issue is a pain if you have to thread it out of state, but if you get a pre-threaded model or have a convenient threading shop in state, I think that you'll find it much easier to shoot accurately than any of the above.

What did you get OP?

Sig Mosquito and Walther P-22 is made of zinc; there are failures, mostly slides.
Ruger or Buckmark is the way, or CZ Kadet to more money.

I would recommend the Ruger as a factory host. I also have a Buckmark which is excellent. My wife's Walther P22 sucks, it will only function reasonably reliably with Stingers and isn't particularly accurate. I've only shot a Mosquito once and it was ok but they have a bad rep too.

Out of your three listed options, I would go with the Ruger. I think it's a better pistol than those other two.

That said I would go with a Buckmark over a Ruger, and if you were willing to spend the bucks I'd go with a CZ Kadet over a Buckmark.

Ruger 22/45 is my vote.  AAC Prodigy, Burris Fastfire II, and a TLR-1 (put my TLR-3 on another gun since the picture).  Fun to shoot the varmints as it gets dark

Is that a 22/45 MkIII factory threaded model that originally had the rails on top and bottom that you added fixed sights to or is it the fixed sight model that you added a bottom rail to? I haven't seen the factory setup like that.

I liked the fixed sights and i wasn't planning on an optic, but i also wanted the bottom rail so i picked up the fixed sight and after that i bought the bottom rail direct from Ruger - I think it cost me around $20 shipped

Was your fixed sight model drilled and tapped for the bottom rail? Mine only has the DT spots for a top rail.

I had a gunsmith drill and tap it for the bottom rail

I've been hearing rave reviews about the S&W model 41.  Supposedly it has extremely quiet action noise.  

Accurate Ordnance has done some custom threading jobs and documented it here.  http://accurateordnance.com/cgi-bin/imcart/read.cgi?article_id=11&sub=4

With that being said I have a Ruger Mark III with a pac lite upper and I couldnt be happier.  With my silencerco sparrow it is very quiet!

After much research and talking to Dealer friends and actual shooters seeking to answer your very same question, I went with the Ruger MarkIII 45/22. Once I installed a Fast Fire II Sight and my 5.56 can,I was amazed at the accuracy and the absence of any loud report. Real close to movie quiet. I am waiting on a Gemtech  G5-22 can and I understand it will be quieter than my 5.56 can. Lots of FUN!!!!
The Ruger is a little heavy for a .22 pistol but is well made more like a tank and I expect many years of reliable service. Check one out.

Old pic of my 22/45 and AAC Element.  It's currently wearing a Bushnell TRD for an optic.  

Browning Buckmark

I have the ruger 22/45 and a P22. Very happy with the 22/45, not very happy with the P22. I have also heard good things about the Sig 1911 22lr.

Thanks for the input guys.  I've settled on the ruger.  It's stupid lite with the element and balances very nicely.

They will be threading my Marlin 25N.  I can't wait to shoot it with a element mounted on it.

I went with the Ruger as well and have been running my YHM 556 suppressor on it. Little bulky but quite and I can go back and forth between it and my AR
Fun to shoot and just one can.