I, personally, believe that "enough" is:
1) Having at least 1 "all-around/multi-role" pistol (I.E. mid to high cap CC or HD pistol in .380, 9mm, .40, .45, .357, 10mm, etc.) *Bold-faced because this is the most important gun any gun owner should own, the basic of the basic, the most necessary of all necessities gun-related needs*
2) After full-filling criteria 1, having at least 1 "all-around/multi-role" shotgun (I.E. a pump or semi in 12-ga, 20-ga, etc.)
3) After full-filling criteria 1 & 2, having at least 1 "all-around/multi-role" rifle (I.E. semi-auto rifle in .223, 7.62x39, 7.62x51, etc.)
4) After full-filling criteria 1-3, having at least 1 rifle chambered in .22
5) After full-filling criteria 1-4, having at least 1 pistol chambered in .22
6) After full-filling criteria 1-5, having at least 1 "Hiking/trail" revolver/wheel gun (I.E. in .44mag, 10mm, .454 casul, etc.)
7) After full-filling criteria 1-6, having at least 1 hunting/long-range/precision rifle (I.E. a scoped, bolt-action in .270, 7mm, .308, .30-06, etc.)
Anything else is not necessarily "necessary." Anything else is an impulse buy or considered a "fun gun."