Well I would break it down like this.....
1911 a must have
Metal frame wonder 9 (bhp, cz, Beretta etc)
Polymer gun (glock, m&p, h&k, etc)
Wheel gun (ruger, s&w, colt, alpha etc)
22lr (rugers, browning, wheel guns, whatever)
Then we all need that piece of jewelry that we love to look at. (Sig 210, high end 1911, collector SAA, collector Colt wheel gun, War Era collectable etc whatever floats your boat)
Then you need to have that one gun your just trying out to see if you "like it"
So really as I see it we all need at LEAST 7 handguns at anyone time.