Once I hit 40 rifles I slowed down quite a bit. Now I mostly look for pretty guns rather than useful guns. I could probably get by with a dozen or so if I absolutely had to though.
Got to have some .22's for cheap plinking
Need a .223 for shooting 3 gun and for HD, and you need a spare, and a backup for the spare
A small bore for hunting in something like .243 or 25-06, really a coyote gun for long range shots ,would be useful if it could also do long range paper punching
A couple of medium bores for hunting, something like a 7x57/280/270
And some .30's, I mean you're just not a gunnie without a couple of .30's, I like the .300 Savage, .308, 30-06 and .300 Winnie
A true medium bore in .338 or .35 is also handy for elk and bear hunting
Then at least one big bore, and I'll even let the .375 H&H slide in here, 'cause you never know when you'll wind up in Africa
Then a couple of fun guns, maybe a 45-70 1885 Browning, .50 Beowulf, .45 ACP and 9mm carbines, just because life should be fun
And a couple of pretty guns, just because you're out hunting doesn't mean you can't look good too.