Gold, according to the late night conspiracy radio types and the commercials that their sponsors run, MDK. Once Y2K hits they say we're going to need it along with two decades worth of their version of MRE's.
Let's see "Dead Air Radio"? Taken, along with "Dead Cat Radio". "Alzheimers Network"? TV network that runs on loop in many doctors offices. "Pinwheel Radio" may conflict in call letters with the often used "Pissweak Radio" a favorite of hams and dx'ers alike in all it's incarnations. It could work as it's open for grabs, but you've always got some crank out there who might complain.
Personally, if I were you, I'd go with "Son Of Smilkstein Radio". Built in audience and free request lines at A&P grocery stores nationwide.