I currently own maybe 20+ semi-auto .22 pistols, and dozens of others have gone away.
All of them will, when shot often enough and with different types of ammunition, will have failure to feed (FTF) issues at some point. It might mean a good cleaning, a bit of lubrication, or most likely a change of ammunition. Some lower grade ammo will work out of one batch lot, than not so well out of the next box.
The largest contributor to FTF in any semi-auto, most especially .22's, is shooter error focussed on limp wristing. This is not an assault on an individual's manhood, and I wish there was another phrase to describe it, but suffice to say that this is the major cause of FTF on many semi-autos... centerfires as well. It's amazing to watch otherwise competent combat league shooters compensate around their bad habit of doing this.
Obviously, the most reliable .22 is the revolver.
I've had (and have) several modern Tarus .22 revolvers that all worked fine, my brother bought one last week at Bass Pro- The action was
so bad that they actually refunded his money and took it back! Again- I still have three that are just perfect. Revolvers can be used to shoot any kind of crap ammo, including oddball loads such as "no powder" (sin polvere) little bullets that are great for dispatching squirrels in the attic. Can't do that with a semi-auto. The Aguila Colibri line of ammo is amazing:
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=AU1B222337
Skip .22 Magnum pistols and revolvers- I went through the Colt Trooper Mk.III and the AMT Automag II. A lot of blast and flame, and the elongated dimensions of the .22 mag are not conducive to feeding well in any semi-auto pistol- although my HK300 rifle eats them and spits them out with great effect.
.22 Ammo, by it's dimensions alone, are prone to Failure to Feeds.
Liken it to sinking a golf putt. Round ball, round hole. A .45 ACP bullet is maybe what? 2.25x longer than it is wide? It's stubby fireplug shape is almost square compared to the .22 LR which has a comparatively huge aspect ratio of 4x longer than it is wide. You gotta get that little .22 bullet positioned perfectly in the lips of a precisely seated magazine, then headed damned accurately down that very small feed ramp and chamber throat into a very snug chamber. Where a .45 simply has to fall into place, getting a .22 round to chamber into an autoloader is an engineering marvel.
High Standards made excellent .22's, as they do again today. A good businessman named Alan created High Standard Manufacturing
http://www.highstandard.com/index.html wrested the HS name and designs from a group of clowns who all but ruined their fine name. Avoid the "Mitchell" guns as they are prone to failure due to soft metal in the trigger bars.
I have run through a number of
older High Standard .22 and I have only one caveat. To get additional magazine to function correctly the mags must be "tuned" to the specific weapon in many cases. With newer Texas production, this is not the case.
High Standards, at least the older fine guns, are best bought from a reliable source with an "approval period". The same applies to vintage Smith 41's.
The Walther p22 is a modern elegant little German wristwatch that was primarily designed as a suppressed weapon for GSG-9. It has a nifty feature of the removable sized grip heels. Yes, they can be a little finnicky, some parts are prone to coming loose (front sight and barrel thread protector should be kept tight, but gun won't stop firing even if you do miss them), but they are superb choices for small handed individuals. The short barrel is on mine 100% of the time, the "target barrel" and
fake finned barrel weight are a mounting nightmare. You gotta have a German
Industriapistolen PhD to get one off and on.
The Walther PPK .22 works well almost all of the time, but it's the price of the Fall semester of College books that your kid is going to have to earn on his own. The Luger and P-38 (P-1) 9mm pistols even have excellent conversion units, but now you're encroaching on the Spring semester as well.
The SIG Mosquito is a 7/8th scale of a full sized SIG. The SIG company has also let go a lot of full sized 220, 226, 229 frames with .22 cal conversion units. I got a complete pistol for $350 off of Gunbroker. They all use different sized body .22 magazines and can be found as extras for $30.
I have yet to see a decent conversion unit for a Glock pistol, but the Advantage Arms is the best of the mess. I'm sure Gaston's boys have one on the back burner and will give it to us when Obama outlaws (at first) everything except .22's. Don't think it won't happen... the laws as well as the industry's reaction to it!
My main area of interest is in Colt Service Model Aces, which can be brilliantly reliable (if a bit inaccurate), but not right out of the box. If you can find a
used one and have some desire and knowledge, they can be an absolute hoot. They look like and were designed to kind-of simulate the recoil of a standard .45acp 1911. New In Box examples of this long discontinued toy run well over $1000. (The "Colt Ace" on the other hand begins at $1700 for a beater, and they never worked all that well, anyway) I have seen rough looking finish Service Model Aces go for as little as $450 at the last gun show. That's where I started with my Service Model Ace "shooter", just like my .22 Colt Diamondback 6".
Colt Woodsmen (as mentioned earlier), Huntsmen and the Targetsman are great little guns, but they aren't getting any cheaper each day. Look for one that got put away wet- restore it if you like.
The Ruger 512 is an obvious choice for a good all-round semi auto that won't break the bank. Own one, and remember this well- after you have disassembled it and can't figure out how to make it go back together... try turning it upside down. Avoid the AMT copies. The Ruger is the Model-T of .22 semi autos- everyone and their uncle makes aftermarket toys for them, just like the 10/22 rifles.
I like the Neos, the Buckmark and just about any .22 that is in my hands. Hell, I even liked the Mountain Eagle... and- that Armalite AR-7 pistol ! Remember with "new shooters", none respond well to "limp wristing", a negative technique found often among that crowd.
Still kinda like my long-gone High Standard Sentinel revolver. Had some snake shot in it and then a handfull of hollow points. 9 shots, all guaranteed.
Whatever you pick, never sell it- you'll hate yourself. Own bunches- at least you can still find ammo, albeit nowadays at 4¢ a shot!