Here's a road map I might suggest as a versatile "top 10 list" that would work well for many shooters...with plenty of room to customize the styles and calibers to your own wants and needs:
1) 12ga shotgun
2) 22lr rifle
3) 22-cal centerfire rifle, preferably semi-auto (5.56, 5.45, etc)
4) 30-cal centerfire rifle (30/30, 308, 7mm, 30-06, even 270win)
5) 22lr pistol
6) High capacity 9mm pistol
7) 357mag revolver
8) 45acp pistol, preferably 1911
9) Carry specific pistol that works for you
10) WILD CARD-- get what you like
And if you're on any kind of budget and without an elaborate reloading setup, common calibers and platforms are your friends. "Being different" can be quite an expensive habit, and may leave you lacking parts, accessories, or ammunition.