While Gygax informed by geeky childhood, Clarke tapped my imagination. Did anyone else read the short story "The Nine Million Names of God" (in an anthology of the same name) about a computer doing divine work in a Buddhist monastery? Inspired me as a young man.
So while out of courtesy I won't opine about where Clarke is now -- obviously I have my own ideas -- I can still think of the geosynchronous satellites he first envisioned, looking down from on high. . . .