In my opinion the TWO BEST decades for "The Best" sounding components were the 1920's and the 1970's. The 20's perfected the Direct 'eated Triodes and field coil speakers. The 70' saw the perfection of Japanese solid state audio components. Some experts consider the best equipment to have been manufactured in the '50's or '60's. If you could enter the WAVAC time traveler(pat. pend) with a dumpster sized container(and a pocket of diamonds to cash in at the pawn shop) which decade (or year) would you travel to and fill up the container then return to 2005 with your NOS?
I would also agree with the 50's & 60's but perhaps not so much for the equiptment, but the tubes that went inside of them. Western Electric 300B's Telefunken & Siemens CCA's. Oh if they only had a detatchable power cord.