Must haves on any conceivable list are;
.22 LR
12 gauge
It gets fuzzy after that...
In the east only, I could add;
.243/.308/.358, I like the symetry of a .308 case family.
Or
.257R/7X57/9.3X62, for a little more panach and broader range of applications.
Or
20 gauge/7mm RM/.35 Whelen, considering the amount of shotgunning that I do.
Really, I wouldn't be handicapped with any of those groups.