Sony Rootkit, Sony BetaMax, Sony MiniDisc, Sony ATRAC, Sony Memory Stick [Select / PRO / Duo / PRO Duo / PRO-HG Duo / M2 / XC / PRO-HG Duo HX / WTF], Sony UMD, Sony Elcaset, Sony SDDS, Sony VAIO, Sony Walkman, Sony Discman, [...]
At least they had some lasting success with their Umatic video tape cartridge, and with the CD that they co-developed with Philips. Their Trinitron tubes were unique and generally quite good -- and they lasted as long in the market as any other CRT did, I suppose. And their various iterations of PlayStation console have all been popular despite being Sony products.