The Mark III or 22/45 would be my choice at the moment. But the SR22 gets good reviews. As does the M&P22. The buckmarks should also be considered. The 1911 22lrs (like the sig and gsg) also have gotten pretty good reviews.
Price wise it seems like the all range from 350-400 for most models. Some can be more expensive of course. But seems like 350-400 is a pretty common price point. I picked up my 22/45 for 389 (plus tax). The SR22 they had was like 360, the M&P22 was around the same price.
agreed.
The 22/45 LITE model is very nice (esp. with volquartsen MKII trigger for magazine drop). The SR22 is also very nice as is the S&W M&P22. I don't have any experience with buckmark or the non-22/45 mark III. The LITE, SR22, and M&P22 all come stock with threaded barrels for muzzle devices which is nice. The 22/45 LITE comes with an optics rail which makes it a very fun, sweet, and quick plinker equiped with a small red dot.