I have a Mark III. It's a great little gun, eats whatever I feed it, more accurate than I am, and didn't break the bank. I shoot everything from CCI Minimags to blazer and federal bulk packs. There are a ton of reasonably priced accessories for it, though, as the upper is the serialized receiver, aftermarket uppers aren't really an option here in MA. I have the 5.5" hunter in blue. It has some serious weight to it (42oz, per Ruger), and just soaks up the little recoil a .22lr can provide. Great for beginners.
My only complaint is stripping the gun - it is a bear. Timber was not joking, I purchased a rubber mallet in order to get the receiver off and on the gun. It gets easier once you learn the dance.
I've shot a mark II, it was very similar, though the position of the mag release is more to my liking on the Mark III. Some people rip out all of the lawyer features on the Mark III on principle, if those things bother you the mark II might be a better option. If I start replacing the innards on mine, I may get the parts to remove the mag disconnect, if only to make stripping easier.
I personally like the look of the gun, especially when compared to the 22A.
You may also want to look at the Ruger 22/45. Basically the same gun as the mark ii/iii, but with a plastic/polymer/whatever lower and grip angles and controls meant to mimic the 1911. I've heard it can be a bit heavy on the barrel, but they are less expensive than the mark iii is.