In North America
.22 rimfire, small game
.223 or 5.56x45 varmits,
6.5x55 Swede big game, and larger varmits
338-06 Large game, like Elk, Big Bears
30-30 Win big game, hogs, etc, quick handling, deer, smaller bears
Or
In say Africa
.223
7x57 Mauser
.375 H&H...