But back to Walkmans ... it was really eye-opening how multiple times per year they would release new variations in size and materials and features or just colours, and people would line up or pre-pay to get their hands on them. People who already had Walkmans, often. The brand loyalty was mostly deserved IMO, because Sony was really doing some original R&D.
Personal faves ... compact models in the drop & waterproof Sports line, especially when issued in non-yellow. The solar model was weird, and not super effective, but damn Sony was trying.[1] The metal, and great-sounding Boodo Khan with supplied headphones was also pretty slick.[2] But from a materials and engineering POV there were some gorgeous delicate little metal-body units and at least one was actually the same size as a plastic cassette case itself.[3] (It would expand slightly when you inserted your media.)
Long after I left Sony I tried to keep the brand faith with MiniDiscs for years. But the MD's time has also come and gone...
[1] http://www.walkmancentral.com/products/wm-f107