Elvis Presley's Love Me Tender is probably the hissiest. When I was not consciously sensitive to the bad which is noise reduction, I remember hearing the cleaned-up version in the eighties and thinking, "Wow! They really improved the sound!" It's hiss used to come on like gangbusters off the top, even apparent when heard on AM through a little radio with poor reception. I can't imagine a smash with a more noise to signal ratio, but maybe there were. I'm sure there were at least some pretty hissy hit records. Any come to mind?