Your questions probably is really asking about modern rifle for North American use. For that my search and discussion begins and ends with 30-06. Not imaginative, I know. But can't be argued, it will take anything on the continent and has a huge variety of loadings available.
But, personally, my favorite hunting rifle is a custom built Jaeger styled muzzle loading flintlock in .54 cal. with a lead round ball and propelled by real black powder. Big grizzlies excepted, it will take anything on the continent quite nicely.