Spectrum
Interesting question. Never really thought about it before.
I want rifles, pistols, and revolvers. Shotguns eventually.
I like Browning's pistols and rifles, but to my knowledge they don't do a revolver.
While CZ covers a lot of ground, I don't remember any CZ revolvers either.
S&W does fine revolvers and good auto-pistols, but only a very narrow selection of rifles.
Colt used to do revolvers, and fine ones at that. Their pistols are top drawer. Their rifles are good, but like S&W, very limited selection.
Beretta does outstanding shotgun and pistol work, but I'm not sure about rifles, and I don't believe I've seen a revolver under their name.
Marlin makes my favorite rifle, but no pistols. Likewise Savage, who gave up pistols ages ago.
Remington and Winchester . . . no sidearms.
There are any number of one-hit-wonder manufacturers whose products I like but who don't produce the whole spectrum of firearms.
Which brings me to Ruger, perhaps the most broad-spectrum brand we have. They do single action and double action revolvers, and they're solid products. They do a fairly broad range of auto-pistols, including top quality .22 LR autos and pocket pistols. I really, really wish they'd come out with a 1911-style pistol. They make a couple of my favorite rifles. While I can't say that their whole catalog is blue-ribbon, it covers the important bases and offers acceptable quality.
Kind of a surprise, really. I don't think I'd have said Ruger was my favorite brand for anything other than single action revolvers and .22 auto-pistols.
But, if I'm going to be confined to a single manufacturer, Ruger gets the nod.