I privately study modern (post 1950) product and interior design. Hi-Fi design is of particular interest. To my eyes two Hi-Fi brands are at the pinnacle of design, where form meets function in perfect industrial design.
1. Naim ’olive’ series. This was the Naim design in the 1990s when they were arguably at their peak. So simple, so perfect. The ultimate interpretation of the stripped down ’black box’. Naim were ahead of the curve: their minimalist design which had been part of their DNA since the 70s, was not embraced into wider product design until Johnny Ive created the iPod and Apple made the look ubiquitous. Clean minimalistic interiors moved out of Scandinavia into the rest of Europe in the late 1990s - whilst Naim were there already.
2. Vitus electronics. To the OP - you will know better than anyone the beauty of Scandinavian design if you ran a shop selling it, and to me the Danish Vitus brand is the epitome of sleek, cool, minimalist Scandinavian design. And even better, they make the best sounding amps I have ever heard!