Having endured a few serious shortages of ammo and reloading components, brass and ammo availability are my paramount consideration, which certainly drives this analysis.
5.56/.223 - there will always be ammo of some sort
.308 Win - same, ammo and brass are abundant and this round is like a 1/2 ton pickup, handy for lots of things
.338 Lapua - when more muscle or a longer reach is needed. High quality ammo and brass generally is available. It matches .375 H&H velocitiy and energy with the same weight bullets, but better ballistics
12 gauge - because a shotgun is a necessary tool for bird hunting and home defense and again, ammo is widely available