For me it has to be Boss & Co. The pure craftsmanship and skill that goes into making a pair of Boss Shotguns is absolutely outstanding. They also have a great history and keep their orders really low.
They make a superb rifle aswell. I got to recently handle a Boss in .308 and was it just so well made. A real change from the synthetic rifles I'm so used to.
I wouldn't obviously invest in a rifle by Boss as resale prices are horrendous, but a secondhand shotgun may one day be on the cards, hopefully anyway.