As an owner of both a couple of nice .22 pistols and a big-bore revolver (.44 Magnum), I recommend getting the .22 if you don't have one yet.
The best reasons to buy a .22LR are, IMO:
1) Ruger Single-Six. Way nice revolver, lots of fun with convertible .22LR and .22 WMR cylinders. Really like it in 5 1/2", accurate, well balanced, fun to shoot, scores high on the neat factor. Will make a nice woods gun once I get a good holster for it.
2) Ruger 22/45. Awesome little pistol. Probably more accurate than the Single Six, in all honesty. Kind of feels like a machine-gun in comparison, but still nice. This one has been a many-time woods companion for me.
3) Ruger 10/22. Okay, not a handgun, but still lots of fun and a great tinker-toy, if you like that kind of thing.
4) High Standard. Grandfather has an old one, not sure of the model. Accurate, fun little popper, this one with lots of history to it.
The .44 really is a hoot to shoot, but I find myself less and less inclined to reload lately, so the .22s keep winning their trips to the range instead.