I personally would never want to not have

a 22lr bolt action and a K22 model 18 preferred
a 223 because ammo is so plentiful. My Mini 14 is OK
A 357 revolver, 4" model 19 would be good. Once again. Plentiful ammo
A 308 or 30-06 bolt gun, Ammo availability and big game capable
A Model 25 in 45 acp. Ammo again.
12 gauge pump. Ammo and reliability with any power lever.

I have found a "need" for way more than those, But, with the above I would feel I could handle any situation calling for a gun short of fending off a full on assault.