i'm a fan of the ruger mk2 .22's myself and have a couple of them. one is a 5" gov't target bull barrel and the other is the 6 7/8" slab side target barrel. but, when headed out for a ride in the woods on the atv with my 2 lil boys in tow i grab the s&w 22a-1 that is sitting on top of the freezer in the garage. why seeing that i have 2 other higher quality .22 pistols? in a word weight. the 22a doesnt feel like i have a weapon strapped onto my hip. besides my lil 8 yr old boy loves to run a mag or two thru it at designated stops. so, if for a knockaround gun i would say the s&w 22a series.
good luck with your decision,