The .30-06 is king. There are other chamberings that sell almost as well, but the '06 has been on top for a while. One reason is that it is capable of handling anything you'd come across in North America (with proper placement, of course), all the way up to the big bears. Unless you're going to face charging grizzlies in the Alaskan interior, it should take care ofjust about all of your needs.