I looked at it from two angles:
1) A recommended list for a new shooter that is easing into the game and wants a variety to serve multiple needs.
In that instance my list would be:
A- Instead of the Mosin, a centerfire bolt action in a caliber from .243 to .308...maybe .30-06
B- 10/22....maybe a Marlin M60
C- 12ga pump... any quality brand would do, but the Mossberg or maybe a H&R Pardner would be affordable
D- Glock 19.....because a newer shooter might be easier to break in with the simpler format
2) A seasoned shooter like many here:
(and this would be my list also)
A- AR platform in standard 5.56 (with a .300 barrel as back-up)
B- Marlin 60... because I have found them to be as accurate (if not more than) a standard 10/22 and there are no mags to keep up with. The caveats to that are slower reloads, fewer mods, and no availability for high capacity.
C- 12ga Pump.... I use Winchester 1300's because the prices were right (I have 2 8-shot Defenders that cost $250 for the pair)
D- 1911 style in .45ACP