For me it is about having a real nice example of my favorites . So I've gotten to the point where I don't have alot of stuff but the ones I have have significance to me. My collection so far, an italian SxS and O/U, a Colt goldcup 45, a model 41, a ruger Mark I, k-38, model 88 Winchester, Remington 740, Anchutz 22, Kreiger barrelled AR, Brazo open gun, and a few others totalling about 20.
IMO collecting varitey is the fun part; my goal is to have a collection made up of:
Shotguns - 12, 20 or 16, and 28 or 410 gauge, made up within a mix of SxS, O/U, pump and auto
Pistols - 45 1911, revolver, 22 auto, 9mm auto, .40 auto
Rifle - .30 cal, sub .30, .223 and .22, made up within a mix of auto, bolt, lever and pump
All are reasonably practical for use and that is important to me to.