Breda had a post a little while ago about someone’s shocked horror finding out that Ken Blackwell had SEVEN GUNS! Thinking about it, I figure that you need at least 5 in a basic, but well rounded collection (I need to “finish” my collection.) Shotgun, centerfire rifle and handgun, rimfire rifle and handgun. And probably a second centerfire rifle, (small caliber, .223 range, and a larger caliber) as well as full size and compact handguns.
In the comments, what is your minimum that you would consider to cover the major needs?