Couldn't disagree with anything here. My own preference for a basic "collection" is a bit different.
The necessities:
-A .22lr (preferably lever or semi-auto)
-A .30 caliber centerfire of some type (most commonly a bolt or lever action)
-A muzzleloader
These will let you hunt most anything on the North American continent (except Alaskan stuff, perhaps)
The gravy:
-Smaller caliber centerfire (AR, .22-250, .222, or the like)
-Historical battle rifle - (M1, 1903, Enfield, etc.)
This doesn't include any of the shotguns or pistols I think a good basic collection needs.