If you want to shoot a lot of shells get a ruger markIII .22 caliber
It all depends on what you want to do. Some guys have made good suggestions about a .357 because you can shoot .38 shells as well, but keep in mind that will be a single fire revolver.
The .22 semi is a blast because you can shoot a lot of shells and it has little to no recoil.
Another thing to consider is the price of shells. .22 shells are the cheapest shells you're
going to find. You can get a new markIII for about $600. They are also as accurate as just about any other handgun you will buy in the near vicinity of that price range.
It's a great gun to have, especially if you're going to use it for varmit hunting, target practice, or teaching kids.